SAMUEL  LILIENTHAL,  M.  D., 

230  West  25th  Street. 


THE  PROPERTY  OF 

l  CnllecB  of  tie  Pacific. 


MEDICAL 


A   MANUAL 


OF 


CHEMICAL    PHYSIOLOGY. 


A    MANUAL 


CHEMICAL    PHYSIOLOGY 


ITS  POINTS  OF  CONTACT  WITH 
PATHOLOGY. 


J.    L.  W.   THUDICHUM,  M.I). 


NEW  YORK: 

WILLIAM    WOOD    &    COMPANY, 
27   GREAT   JONES   STREET. 

1872. 

\ 


PREFACE. 


THE  first  part  of  this  little  treatise  was  written  and 
printed  as  the  introduction  to  my  "  Researches  intended 
to  promote  an  Improved  Chemical  Identification  of 
Diseases,"  which  have  been  published  in  several 
numbers  of  the  annual  "  Report  of  the  Medical  Officer 
of  the  Privy  Council."  It  has  been  found  so  useful  in 
my  experience  as  a  teacher,  that  I  have,  with  the 
permission  of  Mr.  Simon,  ventured  to  reproduce  it  in 
the  present  form.  It  is  a  complete  but  concise  epitome 
of  the  branch  of  science  commonly  termed  "  physio- 
logical or  animal  chemistry,"  and  will  be  found  to 
contain  its  latest  acquisitions.  Any  medical  student 
who  possesses  the  information  which  it  contains  will 
be  enabled  to  meet  the  requirements,  so  far  as  concerns 
this  particular  subject,  of  any  of  the  examining  and 
licensing  bodies  in  this  country  and  abroad.  To  the 
student  in  Chemistry,  Physiology,  or  Science,  it  offers 
a  ready  help  to  the  acquisition  of  elementary  know- 
ledge, upon  the  basis  of  which  he  can  afterwards  place 
the  superstructure  of  more  extended  and  detailed 

13555 


VI  PREFACE. 

studies.  To  my  colleagues  of  the  Medical  Profession 
it  will  afford  an  easy  bird's-eye  view  of  the  chemical 
features  of  the  field  of  their  thoughts  and  action.  Its 
perusal  will  involve  no  unreasonable  tax  upon  the  time 
of  any  reader  or  student,  and  occasional  reference  to 
particular  points  is  facilitated  by  marginal  notes  and  a 
short  alphabetical  index. 

The  second  part  of  the  work  is  an  Analytical  Guide 
for  the  use  of  those  who  desire  to  make  themselves 
practically  acquainted  with  the  phenomena  and  con- 
stituents of  animal  bodies.  It  is  therefore  not  de- 
scriptive in  the  sense  in  which  ordinary  chemical  text- 
books may  be  said  to  be  so,  but  prescriptive  in  the  style 
and  manner  of  pharmacopoeias.  It  directs  the  student 
how  to  proceed  in  order  to  arrive  at  a  certain  result, 
leaving  him  in  most  cases  to  appreciate  the  result  of 
his  operation  by  his  own  reflection.  The  guide  is 
perhaps  the  most  elementary  that  could  be  written  for 
any  practical  purpose,  and  yet  I  think  it  improbable 
that  ordinary  students  of  medicine  will  easily  go 
through  the  whole  of  its  matter  in  the  laboratory.  I 
hope,  therefore,  that  teachers  of  chemistry  who  will 
make  use  of  the  Guide  in  their  classes  will  select  the 
reactions  and  analyses  to  be  performed  by  each  student 
according  to  his  knowledge,  ability,  and  intentions. 

This  little  treatise  summarises  much  of  the  method 


PREFACE.  Vll 

pursued,  and  many  of  the  results  arrived  at  in  my 
laboratory  during  many  years  of  patient  inquiry.  In 
the  compilation  of  the  Analytical  Guide  I  have  received 
much  valuable  help  from  my  esteemed  assistants,  Mr. 
F.  J.  M.  Page,  and  Mr.  C.  G.  Stewart,  for  which  I 
here  express  to  them  my  sincere  thanks. 

THE  AUTHOR. 


3,  PEMBROKE  ROAD,  KENSINGTON,  W. ; 
April,  1872. 


CHEMICAL    PHYSIOLOGY, 


AND 


ITS  POINTS  OF  CONTACT  WITH  PATHOLOGY. 


THE  food  of  man,  variously  prepared  by  mechanical  Digestion. 
processes  and  chemical  operations  (cooking),  is  com- 
minuted in  the  mouth  by  chewing.  At  the  same 
time  it  is  mixed  with  a  variety  of  fluids,  some  of 
which  have  chemical  powers  and  predispose  the  food 
to  a  change,  while  others  serve  mechanical  objects 
only.  The  mixture  of  these  fluids  is  termed  saliva ;  saliva. 
but  however  homogeneous  may  appear  that  mixture, 
the  properties  of  its  components  are  very  various. 
For  the  secretion  of  every  particular  kind  of  glands, 
of  which  there  are  four,  differs ,  and  the  secretion 
of  one  and  the  same  gland  or  set  of  glands  may  vary 
according  to  the  agencies  which  call  them  into  action. 
Underneath  the  forepart  of  the  tongue  is  secreted  from 
one  and  the  same  duct  the  saliva  of  a  gland  which 
lies  under  the  tongue  (sublingual) ,  and  that  of  two 
other  glands  which  lie  farther  back  on  both  sides  of 
the  tongue  underneath  the  lower  jaw  (submaxillary 
glands).  To  collect  either  of  these  secretions  little 

1 


2  CHEMICAL   PHYSIOLOGY. 

tubes  have  to  be  carefully  introduced  into  the  respective 
ducts,  which  is  a  matter  of  some  difficulty.  For  this 
reason  the  chemical  composition  of  the  secretions  of 
the  separate  glands  is  very  imperfectly  known.  Ex- 
periments upon  animals  have  shown  that  these  glands 
can  give  four  different  kinds  of  secretion,  according  to 
the  nerves  which  are  irritated  for  the  purpose.  One 
nerve,  a  branch  of  the  facial,  and  a  continuation  of  the 
chord  of  the  tympanum,  on  irritation  causes  a  clear, 
slightly  ropy  secretion  from  the  submaxillary  glands. 

sauTadal  ^is  "chordal"  saliva  contains  about  4  per  cent,  of 
solid  matters,  of  which  1*5  are  globuline,  mucine,  and 
coagulable  albumen ;  2*5  per  cent,  are  mineral,  mainly 
alkaline  chlorides  and  lime-salts ;  of  these  latter  the 
carbonate,  dissolved  in  excess  of  carbonic  acid,  fre- 
quently decomposes  in  the  mouth,  and  deposits  crusts 
of  lime  carbonate  upon  the  teeth,  which  are  popu- 

ia7vaathetic  larty  called  tartar.  On  irritation  of  the  sympathetic 
nerve  the  submaxillary  glands  secrete  an  opaque  very 
tough  saliva.  This  contains  from  15  to  28  per  mille 
of  solids,  amongst  which  is  mucine,  and  granules  or 
roundish  lumps  of  an  albuminous  matter,  and  much 

S!°nic  free  alkali.  The  third  kind  of  saliva  is  that  which 
flows  when  the  submaxillary  ganglion  is  made  the 
centre  of  a  reflex  action  which  works  by  way  of  the 
lingual  nerve.  This  is  the  only  secretory  act  without 
the  intervention  of  cerebro-spinal  influence  that  is 
known  at  present.  The  fourth  kind  of  saliva  is  the 

paralytic  "  paralytic  "  or  thin  watery  fluid  which  is  secreted  under 
the  influence  of  nervous  paralysis,  caused  either  by 
degeneration,  or  poisoning,  or  wounds  which  separate 


CHEMICAL   PHYSIOLOGY.  6 

the  secretory  nerves.  Its  composition  is  not  yet 
ascertained. 

The  mixture  of  sublingual  and  submaxillary  saliva 
in  man  (not  in  animals)  contains  rhodanate  or  sulpho- 
cyanate  (also  termed  rhodanide  or  sulphocyanide)  of 
potassium  and  sodium  C  N  K  S,  and  C  N  Na  S,  recog- 
nised by  the  red  colour  which  iron-chloride  imparts  to 
saliva,  or  to  the  distillate  obtained  from  it  with  acids. 
This  phenomenon  admits  at  present  of  no  particular 
theory. 

The  saliva  which  is  secreted  by  the  parotid  glands  can 
easily  be  collected  by  the  introduction  of  canulae  into 
the  ducts.  It  is  an  alkaline,  hardly  viscous  fluid,  which 
contains  a  little  albumen,  some  globuline,  a  particular 
ferment  termed  ptyaline,  but  no  mucine.  It  contains 
much  rhodanate,  and  is  the  most  suitable  material  for 
preparing  the  distillate  of  rhodanic  acid.  It  contains, 
water  995*3;  solids  4*7;  of  these  are  organic  1*4; 
mineral  3*3  ;  of  the  latter  there  is  lime  carbonate  1/2. 
The  parotid  saliva  transforms  starch  into  sugar  by 
means  of  the  ferment  termed  ptyaline.  This  is  the 
only  agent  in  saliva  which  has  that  power.  It  can  be 
isolated  by  adding  phosphoric  acid  and  subsequently 
lime  to  saliva.  Ptyaline  adheres  to  the  phosphate,  is 
washed  out  by  water,  and  precipitated  by  alcohol.  It 
contains  nitrogen  but  is  not  albuminous,  refusing  to 
yield  the  xanthoproteic  acid  reaction  with  nitric  acid. 
The  diastase  of  malt  has  a  similar  action  used  in  trade 
fermentations.  An  interesting  and  important  applica- 
tion has  lately  been  made  of  diastase  by  Baron  Liebig, 
for  the  production  of  a  food  for  infants,  which  supplies 


4  CHEMICAL   PHYSIOLOGY. 

efficiently  the  want  of  alkali  and  ptyaline  in  the  diges- 
tive juices  of  children  who  are  being  brought  up  with- 
out mother's  milk,  or  with  such  as  is  not  in  a  healthy 
state.  Diastase  acts  best  at  66°  C,  while  ptyaline  is 
destroyed  at  60°  C.  An  agent  similar  to  ptyaline  is 
emulsine,  or  synaptase  of  almonds,  which  has  been 
recommended  as  a  dietetic  remedy  in  diabetes.  But  it 
does  not  seem  to  affect  starch  in  any  way,  although 
decomposing  amygdaline  and  salicine. 

Oil  of  bitter      Prassic 
Amygdaline.  "Water.         almonds.  acid.  Sugar. 


Salicine.  Water.        Saligenine.          Sugar. 


In  these  transformations  sugar  is  a  collateral  pro- 
duct, while  in  that  of  starch  by  ptyaline  or  diastase  it 
is  the  only  product. 

starch.  Starch  consists  of  two  bodies,   which  in  the  little 

granules  are  disposed  in  alternating  layers.  The  first 
is  granulose,  and  has  the  property  of  being  coloured 
blue  at  once  by  free  iodine.  The  second  is  cellulose, 
not  coloured  blue  by  iodine  at  once,  but  only  after 
sulphuric  acid  or  zinc-chloride  has  been  allowed  to  act 
upon  it.  When  unboiled  starch  is  mixed  and  digested 
with  saliva  for  days,  the  granulose  is  dissolved  out  of 
the  corpuscles  and  transformed  into  dextrine  and 
sugar,  and  the  cellulose  only  is  left.  At  higher 
temperatures  this  also  is  changed.  Boiled  starch  is 
more  easily  transformed,  as  the  granules  are  burst  and 
admit  the  altering  juices  between  their  layers  with 


CHEMICAL   PHYSIOLOGY.  5 

facility.  The  first  symptom  of  the  addition  of  saliva 
to  boiled  and  cooled  (to  40°  C)  starch  or  pap  is  increased 
fluidity,  indicating  the  formation  of  soluble  starch  and 
dextrine.  At  a  later  period  only  sugar  is  formed, 
according  to  the  following  formulse  : 

Starch  (synonym  =  amylon)  C6  HIO  05 

Soluble  starch 
Dextrine  .     . 

Dextrine.        Water.          Sugar. 

C        )       H?=  C 


"  £  The  same  formula  as  starch. 


'Amongst  the  products  of  degeneration  of  the  spinal 
marrow  in  locomotor  ataxia,  there  are  bodies  resembling 
starch  corpuscles,  but  consisting  entirely  of  cellulose. 

I  had  an  opportunity  afforded  me  of  examining  such 
a  case,  in  which  the  sense  which  in  physiology  we  now 
term  the  sense  of  pressure  was  almost  entirely  lost, 
while  the  sense  of  pain  and  the  sense  of  heat  and  cold 
persisted.  On  examining  microscopically,  and  by 
means  of  sulphuric  acid  and  iodine,  thin  sections  of 
the  spinal  marrow,  I  found  in  various  parts  of  it  agglo- 
merations of  blue  bodies  imitating  in  a  remarkable 
manner  wheat-starch  coloured  blue  by  iodine.  The 
term  amyloid  is  perfectly  correct  as  applied  to  this 
particular  degeneration.  The  reaction  of  these  bodies, 
however  like  to  that  of  amylum,  is  not  that  of  amylum 
itself,  for  the  latter  is  coloured  blue  by  iodine  alone, 
while  these  bodies  require  the  concurrence  of  sulphuric 
acid  and  iodine. 

The   secretion   of  the   salivary  glands  mixed  with  Mixed  Baliva- 
the    mucus  secreted  by  little   follicles,  in   the   mem- 


6  CHEMICAL   PHYSIOLOGY. 

branes  of  the  cavity  of  the  mouth,  constitutes  mixed 
saliva.  This  can  be  collected  in  quantity  by  irritating 
the  fauces  with  a  feather,  and  producing  vomituritions. 
It  does  not  reduce  alkaline  copper  solution,  but  retains 
a  little  copper  oxyde  in  solution  when  cupric  salt  and 
alkali  only  are  added.  It  transforms  starch  into  sugar, 
so  that  chewed  pap  after  some  standing,  with  cupric 
sulphate  and  caustic  potash,  at  70°  C,  yields  red  copper 
suboxyde.  It  does  not  change  cane-sugar  into  invert 
sugar,  and  thus  differs  from  yeast.  The  quantity  of 
mixed  saliva  secreted  by  a  man  in  24  hours  varies 
between  300  and  1500  grammes ;  it  may  be  greatly 
increased  by  excitants,  and  irritating  medicines  and 
poisons. 

sai^a  in  dia-  Little  is  known  of  saliva  in  disease,  but  the  investiga- 
tions of  the  future  promise  further  results.  In  diseases, 

Anomalous  , .  .  n 

ingredients,  such  as  salivation  under  the  innuence  ot  mercury, 
rhodanates  disappear.  The  saliva  then  contains  mercury. 
Many  medicinal  salts  pass  easily  into  the  saliva  from  the 
blood,  such  as  iodide  and  chlorate  of  potassium,  and 
when  used  long  in  quantity  produce  slight  salivation. 
In  diabetes  the  saliva  contains  lactates,  but  no  sugar. 
In  the  paralytic  saliva  of  hysteric  persons  leucine  has 
been  found.  Acid  saliva  seems  to  contain  lactic  acid, 
and  is  of  course  anomalous.  The  presence  of  urea  has 
been  alleged,  but  not  proved  with  certainty.  In 
hydrophobia  the  saliva  is  the  bearer  of  the  contact- 
poison  by  which  the  disease  is  propagated  to  other 
individuals. 

Digestion  of       While  the  saliva  influences  starch  as  indicated,  and 

starch. 

does  not  lose  its  action  by  the  admixture  of  acid  of 


CHEMICAL   PHYSIOLOGY.  7 

the  concentration  of  the  gastric  juice/it  certainly,  under 
ordinary  circumstances,  does  not  transform  the  whole 
of  the  starch  into  sugar.  The  gastric  juice  has  no  in- 
fluence on  starch;  the  pancreatic  juice  a  trifling  influence 
in  the  same  sense  as  saliva.  Deducting  all  sugar  and 
lactic  acid  to  be  met  with,  it  is  necessary  to  assume 
that  other  products  are  formed,  which  yet  elude 
analysis.  Do  any  of  these  products  find  their  way  into 
the  liver,  and  are  these  transformed  into  glycogen  ? 

G-lycogenis  a  kind  of  dextrine,  which  was  discovered  Sf£nof 
in  the  liver  by  Bernard  and  Hensen.  It  occurs  in  three 
forms,  of  which  one  of  the  formula  C6H1005,  is  powdery, 
two  others,  C6H1206,  and  C6H1407,  are  gummy.  It 
polarises  to  the  right  four  times  more  intensely  than 
dextrose  sugar.  "With  a  solution  of  iodine  in  iodide  it 
gives  a  dark  red  colour.  It  dissolves  copper  oxyde 
without  reducing  it.  By  sulphuric  and  hydrochloric 
acids,  saliva,  pancreas  juice,  serum  of  blood,  and  cold 
prepared  extract  of  liver,  it  is  transformed  into  dextrine 
and  ultimately  into  sugar.  Many  physiologists  have 
endeavoured  to  explain  the  source  and  destination  of 
this  matter,  but  as  yet  without  any  very  complete 
success.  Regarding  its  origin,  it  has  been  found  that 
it  could  not  be  formed  from  sugar,  as  the  portal  blood 
did  not  contain  any.  It  was  not  formed  from  fats. 
Animal  food  enabled  animals  to  form  it,  whence  the 
conclusion  was  drawn  that  glycogen  originated  in 
albumen.  Seeing  that  the  liver  decomposes  albumen, 
as  proved  by  the  constitution  of  the  bile,  this  idea  has 
much  in  its  favour,  but  the  experiments  upon  which  it 
is  based  admit  of  different  interpretation.  Muscle 


8  CHEMICAL   PHYSIOLOGY. 

frequently  contains  dextrine,  always  inosite  (a  particular 
kind  of  sugar),  and  lactic  acid.  All  these  might 
enable  the  liver  of  the  animal  which  eats  the  flesh  to 
form  glycogen.  At  present  it  is  uncertain  from 
which  material  the  liver  forms  glycogen ;  possibly  it  is 
formed  out  of  starchy  and  albuminous  matters  at  the 
same  time ;  at  least  most  of  it  is  formed  (up  to  12  per 
cent,  of  the  weight  of  the  liver  in  fowls)  when  these  two 
kinds  of  food  are  digested  together  in  large  quantity. 

As  the  dead  liver  was  found  to  transform  glycogen 
quickly  into  sugar,  and  as  some  sugar  could  be  found 
in  hepatic  blood,  it  was  concluded  that  glycogen  is 
transformed  into  sugar,  and  passes  into  the  blood, 
to  be  there  oxydised  or  changed  as  required.  This 
view,  upon  which  was  based  an  entire  theory,  called 
that  of  the  glycogenetic  function  of  the  liver,  was 
received  for  some  years  by  physiologists  in  general, 
until  one  of  its  greatest  admirers,  Pavy,  believed  that 
he  had  discovered  it  to  be  erroneous.  According  to 
him  no  sugar  is  made  in  the  liver  in  the  living  healthy 
body.  I  showed  that  his  experiments  admitted  of  such 
variation  as  to  prove  either  his  or  Bernard's  doctrine. 
At  present  the  bulk  of  evidence  goes  to  show  that,  as 
a  portion  only  of  the  starch  in  the  intestines  is  trans- 
formed into  sugar  and  passes  into  the  chyle,  so  a 
portion  only  of  the  glycogen  of  the  liver  is  transformed 
into  sugar  and  passes  into  the  blood.  Quantitative 
experiments  on  a  large  scale,  combined  with  the 
chemolytic  method  of  research,  will  alone  be  able 
finally  to  decide  the  matters  under  discussion. 
tfou"of8lSS"  When  sugar  in  considerable  quantity  exists  in  the 


CHEMICAL    PHYSIOLOGY.  9 

blood,  the  body  cannot  deal  with  it,  and  excretes  the 
sugar  unchanged.  Such  a  condition  constitutes  the 
disease  termed  diabetes,  which  appears  to  be  a  much Diabetes- 
more  complicated  disease  than  its  main  symptom  taken 
alone  would  seem  to  indicate.  The  oxydation  of  sugar 
only  is  diminished  or  not  accomplished,  that  of  the 
albuminous  substance  and  fats  is  rather  increased, 
sometimes  enormously  so ;  therefore  the  carrying 
power  of  the  blood- corpuscles  for  oxygen  cannot  be 
diminished  as  has  been  supposed  lately,  at  least  not  in 
all  cases  of  diabetes.  There  must  be  a  perversion  of 
chemical  agency,  as  proved  by  the  appearance  of  lactic 
acid  in  the  saliva  and  of  acetone  in  the  stomach  and 
the  urine.  On  the  whole  there  is  at  present  neither  a 
plausible  theory  nor  a  rational  treatment  of  diabetes, 
as  evidenced  by  the  fact  that  noted  physicians  now 
maintain  that  diabetic  patients  eating  promiscuously 
everything  are  better  off  than  patients  who  abstain 
from  starch  and  confine  themselves  to  the  anamylic 
diet  so  elaborately  prescribed  by  Bouchardat.  The 
sugar  may  be  made  in  the  liver  or  in  the  muscles, 
it  may  be  the  effect  of  a  change  of  nervous  influence 
(as  suggested  by  the  artificial  diabetes  of  animals  after 
wounds  of  the  fourth  ventricle  of  the  brain),  or  of  a 
failure  in  the  supply  of  a  ferment  capable  of  transferring 
oxygen  to  it.  The  sugar  when  once  in  the  diabetic 
blood  appears  not  to  be  increased  or  decreased  by 
standing  of  the  drawn  blood  out  of  the  body,  the 
blood  consequently  contains  perhaps  no  glycogen. 
This  was  ascertained  by  a  special  experiment,  made 
upon  the  blood  of  a  diabetic  patient. 


10  CHEMICAL   PHYSIOLOGY. 

SegfoSodTn?if,e  Tne  comminuted  food  mixed  with  saliva  arrives  in 
the  stomach  and  excites  this  organ  to  a  mechanical 
and  chemical  action,  termed  digestion.  The  many- 
little  rennet  glands  situated  in  the  walls  of  the  stomach 

Gastric  juice,  secrete  a  liquid  termed  the  gastric  juice,  which  in  man 
contains  994*6  per  mille  of  water  and  5*39  of  solid  and 
permanently  fluid  ingredients  other  than  water.  Of 
these  3*0  are  pepsine,  0*2  hydrochloric  acid,  with  which 
perhaps  a  small  quantity  of  lactic  acid  is  mixed,  and 
chlorides  of  the  alkalies,  with  some  phosphates  of 
earths.  Singular  is  the  presence  of  some  calcium- 
chloride  in  the  juice.  The  juice  has  been  examined 
mainly  as  obtained  from  persons  who  by  accident 
had  fistulous  openings  in  their  stomachs,  and  upon 
dogs  upon  whom  such  fistulas  had  been  formed  by 
operative  interference.  This  led  to  the  formation 
of  artificial  juice,  which  requires  the  addition  of 
natural  pepsine,  and  is  therefore  only  in  part 
artificial.  It  serves,  however,  for  the  purpose  of 
studying  stomach  digestion  upon  many  kinds  of  food, 
and  of  supplying  a  kind  of  remedy  in  diseased  con- 
ditions in  which  the  natural  juice  is  supposed  to  be 
deficient. 

£ic7ui?egas"  This  gastric  juice  possesses  the  power  of  dissolving 
or  reducing  to  a  liquid  state  albuminous  substances, 
which  are  either  by  preparation,  such  as  boiling,  or  by 
nature,  insoluble  in  water.  Albumen,  caseine,  fibrine, 
syntonine,  the  albuminous  substances  of  vegetables, 
gluten,  and  the  collagene  tissues  or  gristle,  are  under 
the  influence  of  gastric  juice,  or  of  a  mixture  of 
pepsine  and  hydrochloric  acid,  dissolved  to  thickish 


CHEMICAL   PHYSIOLOGY.  11 

somewhat  turbid  matters,  to  which  the  name  of 
peptones  is  given.  Pepsine  may  be  isolated  by  me- Peptone£ 
chanical  precipitation  in  the  same  manner  as  ptyaline 
by  adhesion  to  phosphate  of  lime.  It  is  not  itself 
destroyed  during  digestion,  but  is  capable  of  trans- 
forming great  quantities  of  solids  into  fluid  by  that 
mysterious  influence  termed  contact  action.  When 
the  juice  is  saturated  with  peptones  it  ceases  to  act, 
but  an  addition  of  dilute  acid  fluid  enables  digestion  of 
newly  introduced  albuminous  matters  to  be  effected. 
The  secretion  of  the  hydrochloric  (and  lactic  ?)  acid 
from  the  stomach  glands  is  a  chemolytic  process  by 
which  salts  of  alkalies  are  split  up  into  acid  and 
base.  Of  this  action  I  shall  show  the  completion 
of  the  circle  in  the  biliary  function  immediately  to 
be  described.  The  origin  of  the  pepsine  is  the  blood, 
but  which  ingredient  of  this  fluid  yields  this  curious 
substance,  which  is  so  different  from  albumen,  cannot 
be  told.  In  the  stomach  digestion  saliva  by  its  ptyaline 
forms  some  sugar,  the  gastric  juice  fluidifies  the  albu- 
minous matters,  the  fats  are  made  fluid  and  liberated 
from  their  tissue  connections,  vegetable  structures  are 
variously  disintegrated,  and  the  whole  is  mixed  with 
water  and  a  small  amount  of  air  carried  down  in 
the  process  of  swallowing.  Other  decompositions,  as 
yet  imperfectly  understood,  also  take  place,  as  evi- 
denced by  the  strong  odour  of  the  digested  matters,  and 
at  last  the  homogeneous  mixture  of  substances,  termed 
chyme,  passes  through  the  pylorus  into  the  duodenum. 

The   ingredients  of  chyme  are  starch,   sugar,  fat,  chyme. 
and  peptones,  or  if  only  animal  food  had  been  eaten,  fat  Peptones 


12  CHEMICAL   PHYSIOLOGY. 

and  peptones  alone.  There  are  also  undigested  pieces 
of  flesh,  albumen,  caseine,  constantly  present.  It  is 
at  present  impossible  to  say  what  these  albuminous 
matters  are.  Some  physiologists  say  there  is  only  one 
substance,  others  that  there  are  five  and  more,  the 
statements  as  well  as  the  experiments  upon  which 
they  are  based  being  quite  irreconcileable  with  each 
other.  None  of  these  researches  have  as  yet  been 
carried  out  by  means  of  the  quantitative  chemical 
method,  excepting  the  comparison  of  the  compo- 
sition of  the  peptones  with  the  original  matters. 
It  was  found  to  be  almost  unchanged.  The  pep- 
tone solutions  are  not  coagulated  by  boiling,  but  are 
precipitated  by  absolute  alcohol.  They  give  Millon's 
reaction  with  nitrate  and  nitrite  of  mercury.  They 
diffuse  easily  through  parchment  paper  (dialyse)  into 
water,  exhibiting  a  property  towards  membranes  of 
the  utmost  importance  for  absorption,  which  albumen 
possesses  only  in  the  very  slightest  degree.  Optically 
they  are  characterised  by  turning  the  plane  of  polarisa- 
tion towards  the  left. 

The  coagulation  of  milk  in  the  stomach,  or  by 
rennet  out  of  it,  is  supposed  by  some  to  be  due  not 
to  pepsine,  but  to  another  ferment  which  transforms 
sugar  of  milk  or  lactose  into  lactic  acid,  and  pre- 
cipitates the  soda-albumen  or  caseine.  This  matter 
is  problematical. 

The  quantity  of  gastric  juice  secreted  daily  in  the 
human  stomach  has  been  estimated  at  10  per  cent, 
of  the  body- weight,  or  16  Ibs.;  other  direct  observations, 
however,  lead  to  30  Ibs. 


CHEMICAL   PHYSIOLOGY.  13 

During  digestion  some  gases,  consisting  of  carbonic  Gases. 
acid,  hydrogen,   and  nitrogen,  are  not  rarely  formed 
from  the  digesting   food.     This   may  become   a   dis- 
tressing symptom  in  disease. 

Duodenal  digestion  is  a  continuation  of  stomach 
digestion  under  greatly  complicated  circumstances, 
since  the  chyme  receives  additions  of  bile  and  pancreatic 
juice.  The  physiology  of  these  liquids  has  been  studied 
upon  fistulous  openings  occurring  accidentally  in  man, 
or  produced  by  art  in  animals.  The  secretory  acts 
and  influences  are  no  doubt  well  known,  particularly 
their  variations  under  several  conditions.  But  the 
employment  of  the  secreted  matters  is  by  no  means  so 
elucidated  as  to  be  capable  of  satisfactory  theoretical 
representation.  The  pancreatic  juice  has  probably 
three  functions,  of  which  one  is  the  completion  of  the  6  func" 
solution  of  the  pieces  of  meat  and  albumen  which 
issue  from  the  stomach  with  the  chyme ;  another  is 
the  decomposition  of  fat  into  glycerine  and  fatty  acid ; 
and  a  third  the  emulging  of  neutral  fat,  and  the  trans- 
forming of  it  into  a  subdivided  condition,  in  which  it 
may  pass  through  the  pores  of  the  mucous  membrane 
into  the  chyle-ducts.  It  also  transforms  a  small 
quantity  of  starch  into  sugar.  These  properties  are  only 
possessed  entire  by  juice  which  is  abstracted  from  the 
pancreatic  duct  of  an  animal  during  full  digestion,  or 
from  a  reddened  pancreas.  Juice  thus  procured  is 
tough  or  viscid,  and  contains  10  to  11  per  cent,  of 
solids,  while  juice  obtained  from  a  permanent  fistula 
has  only  5  per  cent,  of  solids,  and  lacks  the  power 
of  digesting  albuminous  fragments.  It  is  probable  that 


14  CHEMICAL   PHYSIOLOGY. 

this  deficiency  is  caused  by  a  degeneration  of  the  gland 
consequent  upon  the  operative  interference.  The  juice 
contains  an  albuminous  matter  at  present  undefined, 
possibly  some  mucine,  and  generally  leucine,  which  is 
present  in  the  parenchyma  of  the  gland  in  larger  quanti- 
ties :  it  has  a  more  or  less  alkaline  reaction. 
Sfyfunc"  ^ke  liver  has  an  obvious  function,  and  that  is  to 
secrete  bile.  It  seems  almost  superfluous  to  make 
such  a  statement,  but  the  views  of  physiologists 
regarding  this  organ  have  so  often  been  perverted  that 
it  is  necessary  to  recur  to  elementary  principles.  The 
error  regarding  the  function  of  the  liver  which  has 
crept  into  physiology  has  mainly  been  caused  by  the 
discovery  in  it  of  a  substance  which  has  the  capability 
of  being  transformed  into  sugar,  namely,  the  above- 
described  glycogen,  also  called  hepatine,  or  liver- 
dextrine  ;  and  in  consequence  of  that  in  itself  remark- 
able and  interesting  discovery  it  has  generally  been 
believed  that  the  main  function  of  the  liver  was  that  of 
forming  sugar.  We  know  now  that  such  is  not  the 
case.*  The  main  function  of  the  liver  is  one  of 
considerable  intricacy,  and  essentially  connected  with 
the  great  features  of  the  process  of  digestion. 
?tomnaecxh°di.of  Digestion  in  the  stomach  is  produced  by  a  process 
fS  S?e  fiuic-  in  which  of  chemical  ingredients  hydrochloric  acid 

tion. 

*  See  the  articles  of  Pavy  on  this  subject,  '  Guy's  Hosp.  Rep./  1858, 
iv,  p.  291 ;  '  Phil.  Trans.,'  1860,  p.  595,  and  my  critical  experiments  in 
'  Brit.  Med.  Journ.,'  vol.  i,  1860.  In  these  latter  the  analytical  method 
now  generally  followed  was  first  used  and  published ;  it  was  afterwards 
adopted  by  Pavy,  Bernard,  Kiihne,  and  others.  For  confirmation  of  the 
variable  results  see  Meissner,  '  Jahresbericht  fur,'  1862,  p.  310  et  seq. ; 
Bitter,  '  Zeitschr.  f ,  rat.  Med./  24,  65  ;  Eulenburg,  '  Journ.  fur  Pract. 
Chem./  103, 108,  1868. 


CHEMICAL   PHYSIOLOGY.  15 

takes  a  main  part.  In  the  dog  this  hydrochloric  acid 
is  so  strong  that  the  hardest  bones  are  absolutely 
dissolved.  In  man  such  a  solution  of  bones  cannot 
easily  take  place,  but  they  are  certainly  corroded 
when  introduced  into  the  stomach.  The  acid  which 
dissolves  them  in  the  dog  is  hydrochloric  acid  only ; 
in  man  it  is  probably  a  mixture  of  hydrochloric  and 
lactic  acid.  But  although  we  find  in  the  economy 
chlorides  everywhere,  and  lactates  constantly  in  the 
chyle,  yet  we  do  not  meet  with  these  acids  in  the  free 
state.  We  are  therefore  obliged  to  assume  that  in  the 
walls  of  the  stomach  a  chemical  process  is  constantly 
taking  place  by  which  hydrochloric  and  lactic  acids 
are  formed.  This  process  is  very  simple,  consisting 
in  the  separation  of  the  chlorine  from  sodium  chloride 
(or  common  salt),  and  the  combination  with  it  of  a 
certain  quantity  of  hydrogen  derived  from  the  water. 
What  takes  place  in  the  glands  of  the  stomach  may 
therefore  be  stated  to  be  a  splitting-up  of  water  and 
sodium  chloride,  and  a  cross  combination  of  the 
elements  to  hydrochloric  acid  on  the  one  side  and 
sodium  hydroxyde  on  the  other. 

H20  +    NaCl       =       HOI         +     NaHO 


—  -\        f  -^        (•  -^        f — ^ 

Water.     Common  Salt.     Hydrochloric  acid.     Sod.  hydroxyde. 

The  lactic  acid  is  produced  from  lactates  in  a  similar 
manner,  and  in  the  formula  of  its  formation  the 
place  of  chlorine  in  the  foregoing  formula  would  be 
occupied  by  the  formula  C3H5O3.  This  is  simple 
and  certain.  But  we  find  in  the  body  no  caustic  soda, 


16  CHEMICAL   PHYSIOLOGY. 

or  sodium  hydroxyde,  and  we  are  therefore  driven  to 
inquire  what  becomes  of  it  when  so  produced. 

Before  it  is  carried  away  from  the  gastric  glands  by 
the  blood,  a  part  of  this  sodium  hydroxyde  has  an 
important  function  to  perform,  namely,  to  protect  the 
stomach  against  the  corrosive  action  of  its  own  secre- 
tion,* It  keeps  the  blood  and  tissues  more  alkaline, 
and  prevents  the  acids  and  pepsine,  which  have  become 
more  energetic  after  secretion  and  mixture  with  the 
peptones,  from  corroding  the  texture  of  the  stomach. 
(Such  corrosion  immediately  takes  place  in  cases 
where  the  supply  of  blood  to  a  part  of  the  stomach  is 
interrupted,  or  where  food  remains  in  the  stomach 
undigested  after  the  secretory  energy  has  passed 
away ;  gastric  ulcer,  hematemesis,  chronic  dyspepsia, 
or  painful  digestion  with  follicular  erosion,  and  other 
pathological  conditions,  are  produced  in  this  way.) 
The  sodium  hydroxyde  is  soon  transformed  into 
carbonate  in  the  blood,  and  passes  through  the  gastric 
veins  into  the  portal,  and  thus  into  the  liver.  When 
Bile-  we  analyse  bile  and  add  to  it  a  quantity  of  acid,  we 
precipitate  certain  matters,  namely,  the  biliary  acids 
formed  by  the  liver,  and  the  cholophaeine  ;  and  if  we 
evaporate  the  liquid  we  get  a  large  quantity  of  sodium 
combined  with  the  acid  which  we  have  added.  Sup- 
posing now  we  take  bile  and  add  to  it  hydrochloric 
acid,  we  find  at  the  conclusion  of  our  experiment  that 
sodium  has  been  combining  with  chlorine  and  that  we 

*  This  function  was  clearly  developed  and  stated  by  me  in  '  Brit,  and 
For.  Med.-Chir.  Review,'  October,  1861,  p.  429.  At  a  later  period  it  was 
made  the  theme  of  some  interesting  experimental  inquiries  by  Pavy 
('  Phil.  Trans.,'  1863). 


CHEMICAL   PHYSIOLOGY.  17 

have  sodium  chloride,  and  that  the  hydrogen  of  the 
acid  has  again  combined  with  oxygen  (hydroxyl)  and 
formed  water. 


NaHO  +  HOI  =  NaCI  +  H2O 

That  is  to  say,  by  boiling  bile  with  hydrochloric 
acid  we  reproduce  the  chloride  of  sodium  which  before 
has  been  decomposed  in  the  walls  of  the  stomach.  In 
our  food  we  take  no  salt  of  sodium  combined  with 
biliary  acid,  or  any  acid  that  can  be  transformed  into 
it.  We  take  many  substances  containing  sulphur  and 
nitrogen  which  can  furnish  the  biliary  or  special 
organic  part  of  the  bile,  but  not  the  soda  salts  con- 
tained in  it.  Their  production  is  just  the  function 
of  the  liver.  The  liver  splits  up  or  chemolyses  albu- 
minous substances  or  albumen  into  products  of  which 
a  part  is  at  present  unknown,  another  part,  however, 
well  known  under  the  nsCme  of  biliary  acids  and  coloured 
ingredients.  They  are  taurocholic  acid,  glykocholic 
acid,  cholophseine,  bilifuscine,  biliprasine,  choline, 
lecithine,  and  cholesterine. 

Taurocholic  acid  (02aH45lf07S)  contains  all  the 
sulphur  of  the  bile.  By  this  ingredient  it  manifests 
itself  as  a  derivate  of  albumen,  which  also  contains 
sulphur.  Glykocholic  acid  (C26H43N06)  is  nitrogenous 
only,  and  free  from  sulphur.  Both  acids  yield  by 
chemylosis  an  acid  free  from  nitrogen  and  sulphur, 
cholic  acid  (C24H4005).  But  the  sulphuretted  acid  yields 
as  the  second  product  a  body  containing  all  the  sulphur 
and  nitrogen  of  the  original  acid,  namely,  taurine= 
C3H7]Sr03S  =  dehydrated  isaethionate  of  ammonia,  and 

2 


18  CHEMICAL   PHYSIOLOGY. 

producible  from  such ;  while  the  other  compound  acid 
yields  as  the  second  product  of  its  cleavage  glykokoll 
or  amido-acetic  acid  (C3H5N03),  which  is  producible 
artificially  by  various  processes.  The  rational  con- 
stitution of  the  smaller  nuclei  is  thus  shown  to  be 
well  known ;  but  the  same  could  not  be  said  of  cholic 
acid.  Glykokoll  appears  in  an  excretion  as  hippuric 
acid  (in  which  it  is  coupled  with  benzoic)  but  it  is  at 
present  uncertain  whether  this  excreted  glykokoll  has 
previously  taken  any  share  in  the  composition  of  bile 
or  not.  Taurine,  however,  is  consumed  in  the  body, 
and  its  sulphur  appears  in  the  excretion  as  sulphuric 
acid. 

The  coloured  ingredients  of  bile  are  cholophaeine 
or  bilirubine,  C9H9N03,  and  bilifuscine,  probably 
C9H11N03.  By  oxydation  and  loss  of  carbonic  acid 
cholophasine  easily  passes  into  biliverdine,  C8H9N03, 
according  to  the  formula,  C9H9N02  +  20  =  C8H9lSr03 
+  C02. 

Cholesterine  (C^H^O)  occurring  in  the  brain  and 
blood  is  no  doubt  excreted  by  means  of  the  bile.  It  is 
a  polydynamic  alcohol,  capable  of  forming  ethers 
analogous  to  fats.  Coloured  matters,  such  as  cholo- 
nematine,  boviprasine,  fuscopittine,  muscoprasine, 
and  ethochlorine,  all  possessing  characteristic  pro- 
perties and  spectra,  and  cholesterine  are  the  main 
residues  of  certain  diseased  processes  which  terminate 
in  the  production  of  calculi.  In  a  degeneration  of  the 
liver,  called  bacony,  considerable  quantities  of  chole- 
sterine remain  stagnant  in  the  parenchyma  of  that 
organ.  The  choline  of  the  bile  is  an  organic  base  of 


CHEMICAL   PHYSIOLOGY.  19 

the  composition  05H15N02.  It  is  closely  related  to 
neurine,  C5H13N,  a  base  obtainable,  together  with 
choline,  from  cerebric  acid  or  lecithine,  and  we  are 
justified  in  assuming  that  it  is  derived  from  the  de- 
composition of  that  body.  Lecithine  consequently 
may  be  considered  as  a  normal  ingredient  of  bile. 

The  biliary  acids  yield  a  particular  test,  called,  after 
its  discoverer,  Pettenkofer's  reaction.  When  mixed 
with  sugar  and  sulphuric  acid  they  produce  a  splendid 
purple  colour.  It  has  been  found  that  other  acids, 
such  as  lithofellic,  also  yield  this  test ;  and  I  found, 
further,  that  cerebric  acid  yielded  it  with  rare  in- 
tensity. I  therefore  applied  the  spectroscope,  and  was 
glad  to  discover  some  means  for  the  distinction  of  the 
various  acids  in  the  coloured  test  solution.  The  biliary 
acids  show  two  bands,  cerebric  acid  and  vitelline  only 
one.  These  spectra  are,  however,  difficult  to  observe, 
and  require  sunlight  or  oxhydrogen  light  for  their 
complete  development. 

The  quantity  of  bile  secreted  in  the  human  body  in 
a  day  has  been  estimated  at  1200  grammes,  or  the 
bulk  which  would  fill  a  wine  bottle  and  a  half.  Con- 
clusions from  quantities  observed  in  animals  can  only 
be  used  with  caution,  as  some  animals,  e.  g.,  the  guinea- 
pig,  produce  enormous  quantities  of  bile  relatively  to 
their  body  weight,  while  dogs  and  sheep  produce 
relatively  small  quantities.  The  production  is  more 
likely  to  stand  in  proportion  to  the  size  and  weight  of 
the  liver  (hitherto  neglected  as  a  physiological  factor) 
than  to  the  weight  of  the  body,  to  which  hitherto 
quantities  were  almost  exclusively  referred. 


20  CHEMICAL   PHYSIOLOGY. 

The biie  inthe      The  function  of  the  bile  is  evidently  like  its  chemical 

intestine. 

constitution,  very  complicated.  Stored  during  inter- 
vals between  digestion,  it  is  mainly  secreted  as  well  as 
expelled  from  the  gall  bladder  during  digestion,  and  a 
particular  quantity  of  it  during  a  peculiar  episode  at 
the  end  of  the  emptying  of  the  stomach.  On  being 
mixed  with  the  acid  of  the  chyme,  the  biliary  acids  are 
set  free,  but  not  precipitated,  as  the  soluble  taurocholic 
acid  holds  the  glykocholic  in  solution.  But  a  pre- 
cipitate of  peptones  is  nevertheless  produced  in  the 

?ones°fpep~  mixture  of  chyme  and  bile.  This,  mixed  with  the  bile- 
acids  and  the  biliary  colouring  matter,  passes  along 
the  intestine  as  a  resinous  adhesive  substance,  to  be 
altered  and  made  absorbable  by  the  many  influences 
of  intestinal  reaction.  It  is  soluble  in  alkali,  and  as 
much  of  the  intestinal  secretion  besides  gastric  juice  is 
alkaline,  the  transformation  meets  with  no  difficulty. 
The  peptone  then  may  pass  into  blood  and  chyle  as 
albumen  and  fibrinogen  and  nbrinoplastic  matter,  but 
the  bile  is  not  so  easily  accounted  for.  The  acids 

biiTges  (  certainly  split  up,  taurine  and  glykokoll  returning  into 
the  circulation,  but  the  cholic  acid  mainly  disappears, 
without  leaving  any  trace  in  the  blood  or  chyle; 
neither  contain  a  trace  of  biliary  matter.  In  the  faeces 
only  occurs  a  small  proportion  of  the  cholic  acid, 
amounting  in  man  to  from  two  to  three  grammes, 
being  perhaps  one  eighth  or  one  twelfth  of  the  entire 
amount  secreted.  The  cholophaeine  has  been  also 
changed  and  become  insoluble  in  chloroform.  We 
must  therefore  assume  that  the  cholic  acid  is  already 
split  up  or  chemolysed  in  the  intestine,  and  reaches 


CHEMICAL    PHYSIOLOGY.  21 

the  circulation  in  the  more  simple  form  of  products  of 
its  decomposition.  The  bile  influences  fats  and  fatty- 
acids  in  the  manner  of  a  soap.  It  communicates  to 
the  small  absorbing  tubes  an  attraction  for  fat,  so  that 
capillarity  raises  the  fat  to  a  higher  point  than  the 
same  vessel  would  do  without  bile.  Bile  then  re- 
presents the  accomplishment  of  a  purpose  which  we 
term  chemolysis  of  albumen.  But  the  further  uses  of 
bile  are  numerous  and  important ;  the  excretion  of 
cholesterine,  intimately  related  to  the  chemistry  of  the 
nerves,  and  possibly  a  product  of  their  action;  the 
excretion  of  choline  and  probably  lecithine,  of  which  the 
objects  are  continuous ;  the  excretion  of  cholophgeine,  eases.11 
of  which  the  objects  are  at  least  obscure.  Bile  pre- 
cipitates pepsine,  and  when  it  regurgitates  into  the 
stomach  arrests  digestion  completely.  It  therefore 
puts  an  end  to  pepsine  digestion  in  the  duodenum,  and 
favours  the  alkaline  pancreas-digestion.  In  disease 
the  bile  may  be  retained  and  cause  jaundice,  and 
slowness  of  the  pulse ;  or  it  may  be  decomposed  in  a 
peculiar  mannner  and  produce  concretions ;  in  man 
these  consist  of  cholesterine  and  modified  bile-acid, 
and  bilifuscine,  with  cholophaBine  and  earths ;  in  oxen 
the  cholophasinate  of  lime  predominates,  and  modified 
bile-acids  with  lime-soaps  are  in  lesser  quantity.  In 
pigs  these  calculi  contain  a  peculiar  lime  salt  which 
assumes  a  voluminous  crystalline  form,  when  the 
powder  is  digested  with  cold  alcohol.  The  pancreas  ?£££** 
has  in  diseases  been  observed  to  be  degenerated  and 
cancerous ;  and  as  in  these  cases  lumps  of  fat  are 
stated  to  have  been  observed  in  the  fasces,  this  ap- 


22  CHEMICAL   PHYSIOLOGY. 

pearance  of  fat  has  been  ascribed  to  the  failure  in  the 
supply  of  pancreas-juice.  In  lientery  the  pancreas  as 
well  as  the  stomach  and  pylorus  is  probably  at  fault. 

^e  digestion  in  the  small  intestine  is  very  imper- 
fectly known,  and  requires  particular  and  great  re- 
searches in  the  future.  In  this  part  of  the  body  is  the 
constant  and  principal  seat  of  diseased  processes  of  the 
greatest  importance,  e.  g.9  typhus  and  typhoid  fever, 
cholera,  and  others,  not  the  least  important  amongst 
them  the  aestival  and  autumnal  diarrhoea  so  fatal  to 
many  persons  in  every  year  without  special  epidemic 
influences. 

humanfand  Glycerine  is  a  tridynamic  alcohol,  constructed  ac- 
body'  cording  to  the  type  of  water  thrice  condensed.  In  this 
type  there  are  six  atoms  of  hydrogen  replaceable ; 
when  three  of  these  are  replaced  by  the  tridynamic 
radical  glyceryl,  glycerine  is  formed.  Glycerine, 
therefore,  has  three  atoms  of  typical  hydrogen, 
which  can  be  replaced  by  three  atoms  of  a  mono- 
dynamic  body  or  one  atom  of  a  tridynamic  body.  It 
is  not  necessary  to  substitute  all  the  hydrogen  at  once 
when  we  work  synthetically,  but  in  animal  bodies  all 
the  hydrogen  is  always  replaced  by  fatty  acids.  A  fat 
is  thus  shown  to  be  a  body  of  the  type  of  three  atoms 
of  water  condensed  to  one,  thus — 


in  which  three  atoms  of  hydrogen  are  replaced  by  one 
atom  of  glyceryl111  and  three  others  by  three  atoms  of 


CHEMICAL   PHYSIOLOGY.  23 

fatty  acid  radical.1  Tributyrine,  a  fat  occurring  in 
butter,  has  this  formula : 

3  monodynamic  atoms  of  butyryl  =  (C^H^O)1 

(C4H70)<  L 

1  tridynamic  atom  of  glyceryl       =  (C3H5)ni  ^ 

held  together  by  three  didynamic  atoms  of  typical 
oxygen. 

The  Roman  numeral  to  the  right  of  the  radical  buty- 
ryl signifies  that  it  is  a  monodynamic  radical,  and  can 
replace  only  one  atom  of  hydrogen ;  but  the  Roman 
numeral  to  the  right  of  glyceryl  shows  it  to  be  a  tri- 
dynamic radical,  which  by  its  one  atom  replaces  three 
atoms  of  hydrogen. 

The  other  fats  occurring  in  the  human  body  and  in 
animal  food  are  tripalmitine — 

3(C16H810) 
(C3H6)'" 

which  is  equal  to  the  large  formula  of 


jo, 


tristearine,  a  fat  abounding  in  mutton  and  beef,  of  the 
formula 

CsyHnoOg 

and  trieleine,  a  more  fluid  fat,  which  abounds  in  the 
oils  extracted  from  lower  animals  and  vegetable  seeds. 

Yellow  animal  fats  contain  luteine,  a  yellow  coloured 
substance  showing  peculiar  absorption  phenomena 
(three  bands)  in  the  blue  part  of  the  solar  spectrum. 

When  these  fats  have  passed  through  the  stomach, 


24  CHEMICAL    PHYSIOLOGY. 

and  after  solution  of  all  tissue  by  which  they  are  held 
together  in  the  parts  of  animals,  arrive  as  fluid  oils  in 
the  intestine,  they  are  acted  upon  by  the  pancreatic 
juice  and  the  bile.  The  former  affects  them  in  two 
ways.  A  small  portion  it  decomposes,  so  that  glycerine 
and  fatty  acid  are  formed,  another  portion  it  emulges, 
or  makes  fit  to  become  subdivided  into  the  very  minu- 
test mechanical  molecules,  and  in  that  state  to  pass 
through  the  small  pores  of  the  cylindric  cells  which 
cover  the  villi  of  the  intestine.  The  fatty  acids  mostly 
combine  with  soda  and  pass  as  soaps  into  the  venous 
blood,  and  with  this  to  the  liver ;  while  the  emulged 
neutral  fats  pass  into  the  lymphducts,  and  by  them  into 
the  venous  blood,  without  passing  through  the  liver. 
After  incorporation  with  the  blood  the  fat  is  burned  up 
in  the  system,  particularly  the  muscles. 

emuff'of  -^u^  ^nere  ig  ye^  a  particular  form  in  which  fatty 
pXiticnd  acid  is  found  in  the  body,  namely,  emulged  in  phos- 
phate of  sodium  solution.  When  palmitic  or  stearic 
acid  is  boiled  with  common  sodium  phosphate,  it  forms 
a  milky  fluid ;  the  acid  is  so  finely  subdivided  that  the 
microscope  can  distinguish  only  the  very  finest  mole- 
cules. When  this  process  is  applied  to  neutral  fats, 
,  or  to  oleic  acid,  no  effect  is  produced.  The  emulsion 
is  a  very  loose  combination,  inasmuch  as  ether  extracts 
the  fatty  acids.  This  particular  form  of  fatty  acid 
emulsion  occurs  in  lipohsemia,  or  fatty  blood  disease, 
in  chylous  urine,  and  in  several  effusions  into  internal 
cavities.*  Its  formation  is  a  normal  occurrence,  the 
phosphate  of  sodium  of  the  food  (bread)  yielding  the 

*  Compare  on  this  subject  my  researches  published  in  the  '  Lancet.' 


CHEMICAL   PHYSIOLOGY.  25 

mineral  ingredients  for  the  carrying  on  of  the  process 
with  the  digested  fat  in  the  intestinal  canal;  if  the 
phosphate  be  wanting  in  the  food,  the  bile  which  always 
contains  notable  quantities,  will  supply  it  [and  it  is  to 
this  action  of  the  phosphate  in  bile  that  any  influence 
upon  fatty  acids  which  it  possesses  is  due,  the  action 
upon  neutral  fats  formerly  ascribed  to  it  being  an 
erroneous  conception].  The  anomaly  in  the  above- 
mentioned  diseases  is  the  persistence  of  the  fatty 
emulsion  in  the  arterial  blood,  whereby  an  obstruction 
of  the  circulation  and  consequent  effusion  (of  blood, 
serum,  fatty  and  fibrinous  serum,  as  in  apoplexy, 
dropsy,  chylous  urine,  and  other  diseases)  is  produced. 

Fat  having  been  frequently  found  in  degenerating 
tissues,  deposited  in  a  visible  manner,  in  parts  where 
healthy  structure  shows  no  visible  fat,  microscopic 
anatomists  admitted  a  particular  fatty  degeneration,  in 
which  fat  in  excess  assumed  the  place  of  albuminous 
matters.  The  heart  was  supposed  to  be  particularly 
subject  to  this  disease,  to  which,  however,  all  other 
tissues  paid  tribute.  This  doctrine,  however,  is  at  pre- 
sent in  a  very  unsatisfactory  state,  and  requires  much 
elucidation  by  researches  conducted  upon  mathematical 
principles.  That  fatty  degeneration  so  called  may  be 
a  very  complicated  chemical  disorder,  I  showed  many 
years  ago  by  the  demonstration  of  changes  in  the 
myochrome  of  the  muscles  of  the  heart,  which  produced 
a  green  granular  pigment.* 

Chyle  is  the  fluid  which  the  lymphatic  vessels  of  the  cnyie 

*  See  '  Trans,  of  the  Path.  Soc.,'  vol.  vi,  1856,  p.  141,  and  '  Quart. 
Mic.  Journ.,'  vol.  iv,  1856,  p.  111. 


26  CHEMICAL   PHYSIOLOGY. 

villi  of  the  intestine  absorb  from  the  digested  food  and 
carry  to  the  blood.  It  contains  much  fat,  to  which  it 
owes  its  white  milky  appearance.  It  further  contains 
the  ingredients  for  the  formation  of  fibrine,  and  curdles 
soon  after  it  is  withdrawn  from  circulation.  Then 
there  is  potassium-albumen,  and  the  ordinary  albumen 
of  serum.  There  are  also  lactates,  sugar,  and  urea 
contained  in  chyle,  besides  a  certain  amount  of  alkaline 
salts.  Chyle  is  the  material  by  means  of  which  the 
blood  is  constantly  renewed.  It  contains  mostly  some 
white  and  red  blood-corpuscles,  which  leads  to  the  idea 
that  they  might  perhaps  be  formed  in  certain  lymphatic 
glands  through  which  the  chyle  has  to  pass.  Before 
entering  the  blood,  chyle  is  always  mixed  with  a  con- 
siderable quantity  of  lymph,  which  differs  from  chyle 
only  by  the  absence  of  fat  in  emulsion.  The  lymph  is 
transuded  serum  of  the  blood,  which  penetrates  into 
the  tissues  and  there  performs  its  functions ;  it  is  then 
reabsorbed  and  carried  back  to  the  circulation  by  the 
lymphatic  vessels.  There  are  many  derangements  of 
the  lymph  and  chyle  which  occur  simultaneously  with 
diseased  glands  in  scrophula,  and  in  tuberculosis,  and 
it  is  probable  that  improper  nutrition  has  the  main 
share  in  the  production  of  these  derangements  in  a 
great  number  of  young  children. 

^ke  peculiar  shape  of  the  blood  corpuscles  appears 
biooJf-cof-  to  be  partly  dependent  upon  their  chemical  constitution. 
This  latter  is  the  product  of  their  own  powers  and 
their  interchange  with  those  of  the  surrounding  serum. 
They  have  a  certain  specific  gravity,  which  is  main- 
tained or  varied  (in  diseases,  in  different  classes  of 


CHEMICAL   PHYSIOLOGY.  27 

animals)  by  the  quantity  of  certain  chemical  ingredients 
which  are  within  them.  Amongst  these  latter  most 
notable  by  its  red  colour,  and  in  the  first  place  by  its 
chemical  constitution,  is  hematocrystalline.*  This  sub- 
stance contains  carbon,  hydrogen,  nitrogen,  iron,  sul- 

-,  -,  .  .'._._ 

phur,  and  oxygen,  in  the  proportions  indicated  by 
the  following  formula :  C600H960N154FeS30177.  This 
leads  to  an  atomic  weight  of  13,280,  or  if  it  be  deter- 
mined by  the  quantity  of  that  most  stable  element, 
iron,  an  atomic  weight  of  about  13,000.  Persons 
who  have  not  studied  this  branch  of  chemistry,  and 
who  perhaps  in  their  handbook,  do  not  read  of  atomic 
weights  rising  above  500,  may  wonder  at  the  high 
atomic  weight  here  assigned  to  hematocrystalline. 
But  this  body  can  now  be  obtained  pure  in  quantity, 
and  the  analyses  of  crystals  have  always  shown 
them  to  contain  four  tenths  per  cent,  of  iron.  The 
crystals  are  mostly  of  the  rhombohedric  system, 
and  appear  in  tetrahedra,  octahedra,  with  and  without 
prisms,  or  in  prisms  only.  Their  watery  properly 
diluted  solution,  when  examined  in  the  spectroscope, 
shows  two  remarkable  bands  of  absorption,  and  obscu- 
ration [of  the  blue  and  violet  end  of  the  spectrum. 
As  the  blood  of  all  vertebrate  animals,  when  viewed 

When  the  blood  crystals  were  first  discovered,  and  their  various 
shapes  and  properties  found  out  (Funke,  Kunde),  it  was  believed  and 
stated  (Lehmann)  that  they  consisted  of  a  colourless  substance  (hema- 
toglobuline)  to  which  a  coloured  matter  (hematine)  adhered  like  a  dye. 
As  long  as  the  researches  on  this  subject  moved  on  the  microscopic  field 
only,  this  idea  was  plausible ;  for  many  crystals  are  actually  so  thin  as 
.to  appear  colourless  under  the  microscope.  But  the  chemical  and 
spectroscopical  researches  of  the  last  few  years  have  established  the 
error  of  this  conception  and  substituted  the  doctrine  of  the  text. 


28  CHEMICAL   PHYSIOLOGY. 

within  the  living  blood  vessels,  shows  the  same  bands, 
we  can  assume  that  hematocrystalline  is  present  in  it 
as  such,  and  not  formed  by  the  process  of  preparing 
the  crystals.  Hematocrystalline  can  be  deprived  of  its 
oxygen,  and  then  its  spectrum  changes  to  that  of 
reduced  hematocrystalline.  Shaking  with  oxygen, 
restores  the  double-banded  spectrum.  The  two  bands 

up  into  albu- 

therefore   belong  to  arterial    blood,  the  one  band  to 


venous  blood  (Stokes).  Hematocrystalline  contains  as 
proximate  constituents  an  albuminous  body,  which 
after  separation  remains  amorphous  and  colourless, 
and  hematine,  which  retains  the  colouring  power,  the 
spectral  influence  upon  light,  and  the  iron  of  the 
original  substance,  though  all  varied  in  kind,  proportion 
and  quantity.  Hematine  has  an  atomic  weight  of 
about  620,  and  from  7*5  to  8  per  cent,  of  iron.  It 
occurs  together  with  hematocrystalline  in  the  urine  in 
cruenturesis  (paroxysmal  hematuria).  It  yields 
many  remarkable  products  of  decomposition.  Its 
spectra  in  various  solvents  and  in  the  reduced  state, 
and  the  spectra  of  the  new  derivates,  are  very  charac- 
teristic. The  optical  and  chemical  phenomena  of 
hematocrystalline  and  hematine  are  applicable  to 
medico  -legal  research,  as  affording  the  most  certain 
diagnosis  of  blood  upon  the  smallest  quantities  of 
material.  A  diminution  of  hematocrystalline  in  the 
body  constitutes  the  disease  termed  "  chlorosis"  or 
"  anaemia."  It  is  either  a  specific  ailment,  or  a  sym- 
ptom and  consequence  of  chronic  disorders,  or  acute, 
particularly  tropical  fevers. 
£TioodC-coCr-d  Besides  hematocrystalline  the  blood  corpuscles  con- 

puscles. 


CHEMICAL   PHYSIOLOGY.  29 

tain  a  quantity  of  cerebric  acid  or  of  lecithine.  This 
has  been  variously  called  myeline  (Virchow),  protagon 
(Liebreich),  and  other  names,  but  it  is  probably  the  same 
body  as  that  which  can  be  extracted  from  the  brain.  We 
further  have  in  blood  corpuscles  a  certain  quantity  of  st 
what  is  called  stroma.  This  is  merely  a  name  for  a 
substance  which  is  supposed  to  give  them  a  shape. 
The  stroma  remains  when  the  other  bodies  are 
extracted.  It  is  a  kind  of  chemical  skeleton,  and 
can  be  isolated  (by  freezing,  for  example)  and  investi- 
gated (Rollet).  It  seems  to  be  very  different  from 
the  albuminous  matters  combined  in  hematocrystalline, 
for  it  is  soluble  in  ether,  alcohol,  and  chloroform,  when 
these  agents  are  dissolved  in  serum.  But  it  contains 
a  small  quantity  of  fibrino -plastic  substance  (Alex. 
Schmidt),  namely  paraglobuhne,  sometimes  also  termed  stroma  con- 
globuline.  This  remains  insoluble  when  the  blood- buline> 
corpuscles,  previously  separated  from  serum  by  solu- 
tions of  salt,  are  deprived  of  hematocrystalline  by 
water.  The  gelatinous  paraglobuline,  after  shaking 
with  water  and  ether,  is  soluble  in  solutions  of  salt, 
dilute  alkalies,  and  water  containing  one  per  mille  of 
hydrochloric  acid.  Brought  in  contact  with  fibrino- 
genous  solutions  it  frequently  produces  fibrine. 

The  blood-corpuscles  carry  oxygen,  which  has  great  J]™*faj<rf 
affinity  for  hematocrystalline,  from  the  lungs  to  the corpuscles* 
most  distant  or  hidden  and  internal  parts  of  the  body. 
They  there  yield  it  up  to  the  tissues,  principally  the 
muscles  or  the  oxydisable  matters   contained  in  their 
juices,  and  the  tissues,  thus  oxydised,  return  the  car- 
bonic acid,  water,  urea,  and  other  products  into  the 


30  CHEMICAL   PHYSIOLOGY. 

blood.  The  muscles  may  either  oxydise  immediately 
or  store  the  oxygen  in  large  quantities,  particularly 
during  sleep,  by  means  of  their  red  colouring  matter, 
which  is  identical  with  hematocrystalline.  Although 
the  carbonic  acid  affects  the  colour  and  condition  of 
the  blood-corpuscles,  nevertheless  the  latter  are  not 
carriers  of  the  carbonic  acid.  This  gas  is  in  the  serum. 
carbonic  acid  It  is  there  partly  dissolved  in  the  same  manner  as  in 

is  in  the  * 

soda  or  Seltzer  water,  but  to  a  great  extent  it  is  com- 
bined with  alkaline  bases,  particularly  sodium.  When 
the  blood-corpuscles  of  the  venous  blood  arrive  in  the 
lungs,  they  have  undergone  a  change  which  consists  in 
the  partial  oxydation  of  a  small  quantity  of  their  hema- 
tocrystalline, and  this  is  transformed  into  an  acid 
Hematic  acid.  which  I  will  call  hematic  acid.  This  blood-acid  contains 
nitrogen.  It  is  not  similar  to  any  of  the  acids  we 
know.  It  is  not  volatile  but  fixed  :  it  is  evolved  from 
the  blood-corpuscles  and  passes  into  the  serum  at  the 
very  moment  when  the  former  arrive  in  the  small 
breathing  cells  of  the  lungs.  There  the  blood-acid 
combines  with  the  sodium,  and  the  carbonic  acid  is  set 
free  and  is  left  to  take  its  course,  with  water-vapour, 
through  the  lung  tissue  into  the  respiratory  passages.* 

*  The  excretion  of  carbonic  acid  from,  the  lungs  is  an  act  of  specific 
secretion,  to  which  the  presence  of  oxygen  (and  nitrogen)  may  be  a 
supplementary  advantage  (as  favouring  diffusion),  but  is  not  essential. 
Hiiter's  observation  of  twin  foeti,  which  were  born  living  within  the 
uninjured  membranes  and  surrounded  by  the  liquor  amnii,  and  in  that 
condition  exhaled  gas,  is  to  me  conclusive  evidence  of  this,  as  also  of 
my  proposition  that  the  act  of  first  breathing  is  an  act  of  secretion. 
This  theory  is  fertile  of  explanations  of  many  dark  phenomena,  such  as 
the  peculiar  power  of  newborn  children  to  sustain  prolonged  states  of 
asphyxia. 


CHEMICAL   PHYSIOLOGY.  31 

In  my  research  on   cholera  I  have   shown  that  in  Biooa  change 

•/  m^cnolera. 

that  disease  the  serum  of  the  blood,  being  changed  in 
its  constitution  in  consequence  of  the  alvine  flux,  refuses 
to  perform  the  functions  which  it  performed  before.  It 
exhausts  water  and  other  matters  from  the  blood- 
corpuscles,  and  the  latter  thereupon  cease  to  carry 
oxygen ;  oxydation  does  not  take  place  any  longer, 
hence  the  temperature  falls,  and  the  algid  condition  of 
cholera  is  produced.  In  yellow  fever,  and  in  a  disease 
which  occurs  in  England,  paroxysmal  cruenturesis,  the 
hematocrystalline  of  a  portion  of  the  blood-corpuscles 
leaves  them,  and  in  the  one  disease  decomposes  and 
colours  the  skin  yellow,  in  the  other  appears  in 
the  urine  with  a  red  or  reddish-brown  colour.  A 
similar  decomposition  takes  place  in  some  cases  of 
pygemia,  and  in  poisoning  by  arseniuretted  hydrogen, 
and  by  the  bite  of  venomous  serpents.  Several 
poisons,  such  as  sulphuretted  hydrogen,  carbonic 
oxyde,  hydrocyanic  or  prussic  acid,  kill  or  injure 
by  decomposing  the  hematocrystalline,  or  com- 
bining with  it,  and  keeping  the  oxygen  out.  Thus 
the  study  of  many  diseases  requires  an  intimate  know- 
ledge of  the  constitution  of  the  blood-corpuscles.  The 
value  of  this  we  have  only  just  begun  to  appreciate, 
and  the  chemical  and  optical  methods  of  investigation 
applied  with  rigorous  accuracy  will  bring  us  not  only 
the  explanation  of  normal  phenomena  at  present  re- 
maining obscure,  but  also  useful  practical  information 
on  the  nature  of  diseases,  processes  of  poisoning,  and 
their  treatment  by  prevention  or  cure. 

One  of  the  most  remarkable  properties  of  the  blood  o 


32  CHEMICAL    PHYSIOLOGY. 

is  its  power  of  coagulating  or  setting  shortly  after  it 
has  left  the  body.  Of  this  phenomenon  many  in- 
genious theories  have  been  given,  but  none  has  yet 
satisfied  the  demands  of  exact  chemical  science.  The 
latest  and  most  plausible  one  is  that  of  A.  Schmidt, 
according  to  which  the  serum  contains  two  substances, 
which  have  the  power  of  combining  with  each  other 
to  form  fibrine,  the  substance  which  produces  the 
phenomenon  of  the  curdling  of  the  blood,  as  caseine 
produces  that  of  the  milk.  One  of  these  matters  has 

J 

been  termed  fibrinoplastic  substance  (paraglobuline) 
contained  in  serum  and  corpuscles,  the  other  fibrino- 
gen,  contained  also  in  serum  and  other  fluids  of  the 
body.  There  is  no  doubt  that  substances  answering 
to  these  descriptions  can  be  isolated,  and  when  brought 
together  mostly  form  fibrine.  But  what  is  not  yet 
proved  is  that  they  combine  in  atomic  proportions.  It 
is  just  possible  that  the  paraglobuline  only  acts  as  a 
ferment  like  rennet,  and  transforms  fluid  fibrinogen 
into  gelatinous,  solid,  or  fibrous  fibrine,  by  the  power 
which  in  chemistry  is  termed  contact  action.  But 
even  should  this  theory  be  confirmed  as  at  present 
shaped,  it  would  fail  to  afford  any  answer  to  the 
obvious  question  as  to  the  inhibitory  power  which 
prevents  these  bodies  from  reacting  upon  each  other 
in  the  circulating  blood.  The  cause  of  the  coagu- 
lation being  determined,  would  make  room  for  the 
question  as  to  the  cause  of  the  fluidity  and  non-com- 
bination of  these  bodies  during  life  and  circulation, 
circum-  This  would  no  doubt  be  a  progress,  but  not  a  solution. 

stancesuiider 

is  a  fact  that  blood  while  in  contact  with  the  inner 


CHEMICAL   PHYSIOLOGY.  33 

surface  of  healthy  blood-vessels  in  living  bodies,  even 
when  prevented  from  flowing  by  double  ligatures,  does 
not  coagulate.  Even  coagulated  blood,  when  placed 
into  the  cavity  of  the  excised  heart  of  a  turtle  becomes 
fluid  again.  From  these  and  similar  facts  the  living 
walls  of  blood-vessels  were  said  to  be  the  agencies 
which  kept  the  blood  fluid  (Briicke).  But  such  a 
statement  is  only  a  circumscription,  not  an  explanation 
of  the  fact,  which  therefore  requires  further  study  and 
investigation. 

It  must  always  be  borne  in  mind  that  by  the  method 
of  physiolysis,  or  putrefaction  conducted  upon  certainiysins'.piysic 
principles  and  with  certain  precautions,  fibrine  yields 
albumen,  and  that  consequently  the  atomic  constitution 
of  fibrine  must  be  more  complicated,  and  its  atomic 
weight  higher  than  that  of  albumen. 

The  yellowish  liquid  which  remains  when  the  fibrine 


stitution  of 

has  been  allowed  to  set  in  the  blood,  and  to  enclose  the  serum- 
and   retain  in   its  contracting  meshes  the  blood-cor- 
puscles, is  termed  the  serum.     It   yet   has    a   quan- 
tity of  paraglobuline,  of  which  only  a  small  portion  Paragiobu- 

line. 

has  been  used  up   towards  the  formation  of  fibrine. 

It    further  contains    sodium   albumen   (or   caseine   ofSodiumand 

serum,  Panum),  and  a  very  small  quantity  of  potassium  ESSJT8 

albumen.    The  paraglobuline  is  precipitated  by  carbonic 

acid  from  serum,  diluted  with  10  volumes  of  water,  the 

albuminates  dissolved  in  combination  with  the  alkaline 

metals  are  set  free  by  a  little  acetic  acid.     But  the 

ingredient  of  serum  which   is    present   in  the  largest 

quantity  (7'9  to  9'8  percent.)  is  the  albumen  particular 

to  the  serum,  or  blood  albumen,  as  distinguished  from  serum  aibu- 


34  CHEMICAL    PHYSIOLOGY. 

the  albumen  or  white  of  egg.  This  is  completely 
precipitated  by  boiling  in  the  presence  of  a  little  acetic 
acid.  If  no  acetic  acid  is  present,  sodium  albumen, 
formed  during  the  process  of  coagulation,  remains  in 
solution. 

The  serum  contains  neutral  fats  and  soaps  in  solution 
or  suspension,  in  the  latter  case  being  rendered  milky 
or  turbid  thereby.  In  cases  of  disease  which  I  have 
made  known  the  serum  also  contains  free  fatty  acids. 
-  These  acids  are  emulged  with  the  phosphate  of 
sodium  of  the  serum,  and  after  extraction  by  ether  are 
again  easily  emulged  by  boiling  with  a  solution  of 
common  sodium  phosphate  in  water.  A  similar 
emulsion  I  have  shown  to  occur  in  so-called  chylous 
urine,  and  in  certain  effusions  in  the  scrotum,  termed 
variously  milky  hydrocele  or  lactocele  or  better  lipo- 
rocele.  The  serum  further  contains  cholesterine, 
kreatinine,  urea,  hippuric  and  lactic  acid  in  small  quan- 
tities, and  at  least  one,  perhaps  two,  yellow  colouring 
matters  are  contained  in  it.  In  gout,  uric  acid  as 
urate  of  sodium  and  calcium  is  found  in  it ;  in  diabetes, 
sugar ;  in  jaundice,  biliary  colouring  matter,  or 
cholophseine ;  and  in  leukocythaemia,  formic  acid, 
xanthine  and  other  matters. 

0^  inorganic  salts  the  serum  contains  sodium  chlo- 
ride, sodium  dicarbonate,  and  calcium  phosphate,  small 
quantities  of  magnesium  phosphate,  still  smaller  ones 
of  potassium  salts.  The  chemical  operations  of  the 
serum  (and  blood  on  the  whole)  employ  sodium  salts 
mainly,  while  those  of  the  muscles  mainly  choose 
salts  of  potassium.  We  shall  see  how  the  function  of 


CHEMICAL   PHYSIOLOGY.  35 

the  liver  employs  the  sodium  as  the  principal  mineral 
base  for  its  peculiar  acids.  But  an  explanation  of  this 
strict  separation  has  yet  to  be  found.  We  are  more 
confused  than  enlightened  by  the  discovery  of  the 
apparent  paradox  that  fish,  living  in  a  medium 
abounding  with  sodium  salts,  should  form  a  bile  the 
mineral  base  of  which  is  potassium. 

The  serum  carries  nearly  the  whole  of  the  carbonic 
acid  contained  in  the  blood,  particularly  when  it  be- 
comes venous.  This  is  present  in  two  forms,  the  one 
dissolved  and  removable  by  the  vacuum,  the  other 
combined  with  soda  as  carbonate  and  dicarbonate,  and 
dislodged  only  by  acids  and  boiling.  It  is  also  possible 
that  the  sodium  phosphate  attracts  a  portion  of  car- 
bonic acid  and  holds  it  in  peculiar  loose  combination. 

The  physiology  of  the  gases  of  the  blood,  of  the 
oxygen,  nitrogen,  and  carbonic  acid  contained  in  its 
modifications  of  arterial  and  venous  character,  .has 
lately  been  improved  by  the  invention  of  instruments 
and  methods ;  but  these  do  not  yet  satisfy  all 
demands. 

The  total  quantity  of  blood  contained  and  circulating 
in  a  living  man  has  for  many  years  been  greatly  over- 
estimated,  owing  to  fallacious  conclusions  derived  from 
the  practice  of  bloodletting.  The  best  methods  avail- 
able  about  ten  years  ago  reduced  the  quantity  to  7' 7 
per  cent,  of  the  weight  of  the  body  (Bischoff).  But 
this  has  to  be  again  reduced,  as  in  these  processes  the 
myochrome  was  not  deducted  from  the  hematocrystal- 
line,  by  the  quantity  of  which  the  blood  was  estimated. 
Seven  per  cent,  of  the  weight  of  the  body  will  probably 


36  CHEMICAL   PHYSIOLOGY. 

be  a  more  correct  estimate  of  the  quantity  of  blood 
than  any  other  hitherto  made. 

striated  mus-  rpj^  grated  muscles  consist  of  particular  contractile 
matter,  disposed  in  layers  within  a  fine  membranous 
bag  (sarkolemma)  and  connective  tissue.  The  contrac- 
tile matter  is  arranged  in  disks  consisting  of  syntonine, 
which  are  laid  close  together,  separated  and  surrounded, 
however,  by  a  particular  plasma.  This  can  be  isolated 
from  muscles  treated  at  the  freezing  point,  taken  out 
of  the  animal  just  killed,  or  from  cold-blooded  animals, 

J5assma"  such  as  frogs.  The  plasma  is  alkaline,  and  coagulates 
on  standing  like  blood ;  by  beating  the  coagulation  is 

Myosine.  favoured.  The  coagulum  is  termed  myosine;  it  is 
flaky,  never  fibrous,  and  more  transparent  than  fibrine. 
Plasma  dropped  into  warm  water  coagulates  instan- 
taneously, and  deposits  pure  myosine.  Like  fibrine, 
myosine  decomposes  peroxyde  of  hydrogen.  By  solu- 

syntomne.  tion  in  dilute  acids  it  is  transformed  into  syntonine. 
This  is  the  name  of  the  solid  part  of  the  flesh  tissues, 
the  particular  fibrine  of  flesh  of  Liebig,  which,  insoluble 
in  water,  can  be  extracted  from  the  insoluble  part  of 
meat  by  dilute  acids  in  large  quantities.  The  muscle- 
plasma,  after  coagulation  of  the  myosine,  leaves  the 

swum6"  muscle- serum.  This  becomes  quickly  acid,  like  all 
meat  on  keeping,  and  on  neutralization  deposits  an 
albuminous  substance.  The  fluid  on  acidification  pre- 
cipitates albumen  which  was  in  combination  with 
potassium.  This  precipitation  occurs  in  the  meat 
naturally  by  formation  of  paralactic  acid,  which  at  first 
shares  the  potassium  of  the  phosphate,  and  transforms 
it  into  acid  phosphate.  To  this  belongs  the  acid 


CHEMICAL    PHYSIOLOGY.  37 

reaction  of  kept  meat.  Only  when  excess  of  paralactic 
acid  in  its  free  state  is  present  does  the  albumen 
separate  from  the  potassium-albuminate.  Besides  these 
two  modifications  the  muscle-serum  contains  the  ordi- 
nary serum  albumen  of  blood.  There  is  also  contained  albumen 
in  the  serum  of  the  red-coloured  muscles  a  coloured 
albuminous  matter,  myochrome,  identical  with  hemato- 
crystalline.  In  white  muscles  this  matter  seems  to  be 
absent.  When  flesh  is  extracted  with  water  the  albu- 
minous matters  contained  in  the  solution  are  precipi- 
tated by  boiling  (albumen  curdles  at  65°  C.,  hemato- 
crystalline  only  at  about  90°  C.),anda  faintly  yellow  broth 
is  obtained,  which,  when  made  of  mutton,  retains  that 
name,  but  when  made  of  beef  is  popularly  termed  beef-  Beef-tea. 
tea.  This  mysterious  fluid,  which  is  of  great  dietetic 
value  to  the  healthy  and  the  sick,  contains  a  great 
number  of  remarkable  ingredients — kreatine,  C4H9N302; 
kreatinine,  C4H7N30,  the  former  a  neutral  body,  the 
latter  a  powerful  organic  base,  which  also  appears  in 
the  urinary  excretion  ;  uric  acid,  C5H4N403 ;  xanthine, 
C5H4]SF402 ;  hypoxanthine  or  sarkine,  C5H4N40  ;  gua- 
nine,  C5H5N50 ;  all  of  which  appear  in  the  urine  of 
man  or  of  the  lower  animals  ;  taurine,  the  body  obtain- 
able from  taurocholic  bile- acid,  and  which  may  there- 
fore, perhaps,  be  formed  in  the  muscles,  and  carried  to 
the  liver,  or  be  formed  in  the  liver  and  carried  to  the 
muscles,  or  be  formed  in  both  in  different  ways ;  inosic 
acid,  C6H6lNr205,  and  acids  of  analogous  composition ; 
further  bodies  free  from  nitrogen,  as  paralactic  acid, 
C3H603 ;  formic,  acetic,  and  butyric  acids  ;  glykogen, 
the  same  as  that  in  the  liver ;  dextrine ;  sugar,  or 


lients 
f-tea. 


38  CHEMICAL    PHYSIOLOGY. 

grape-sugar,  and  a  particular  kind  of  sugar  also  found 
in  the  green  shells  of  French  beans,  namely,  inosite, 
C6H1206  +  H30.  The  total  of  these  bodies  which  are 
known  amounts  to  two  grammes  from  the  extract  of 
1000  grammes  of  flesh ;  but  the  total  amount  of  extract 
obtained  is  12  grammes  of  organic  substances.  Con- 
sequently five  sixths  of  the  extract  of  meat  are  at 
present  quite  unknown  to  us.  The  extract  of  the  meat 
of  animals,  oxen  and  sheep,  has  now  become  an  article 
of  wholesale  manufacture  and  of  trade.  It  contains 
about  18  per  cent,  of  salts,  of  which  nearly  half  the 
weight  is  potash ;  less  than  18  per  cent,  of  water,  and 
of  its  dry  residue  60  per  cent,  are  soluble  in  alcohol  of 
80  per  cent,  strength.  The  economic  advantages  of 
this  extract  are  the  direct  result  of  the  purely  scientific 
studies  of  Baron  Liebig,  and  have  made  his  name 
literally  a  household  word.  The  residue  of  the  meat 
from  which  the  extract  has  been  pressed  contains  all 
matters  insoluble  in  water,  syntonine,  myosine,  sarko- 
lemmata,  with  nuclei,  and  fat.  Some  of  this  fat  is 
visible  under  the  microscope  in  the  fibre,  but  some  is 
invisible  and  dissolved,  though  not  as  soap.  The 
residue  contains  phosphate  of  potash  in  insoluble  com- 
bination with  an  organic  matter,  but  no  chlorides. 

The  muscle  is  a  machine  for  the  transformation  of 
chemical  into  mechanical  force,  and  for  the  storing  and 
exercise  of  that  force.  The  exercise  is  partly  constant 
and  involuntary,  partly  intermittent  and  subject  to  the 
will.  The  loaded  muscle  is  alkaline,  full  of  disposable 
oxy disable  matter,  and  of  oxydant,  namely,  oxygen. 
The  nerves  of  motor  influence  effect  chemical  contact 


CHEMICAL   PHYSIOLOGY.  39 

and   immediate  contraction  of  the  various   elements. 
The  muscle  becomes  acid  during  work,  and  gives  off 
large  quantities  of  carbonic  acid.     The  disintegration 
of  its  albuminous  matter  seems  hardly  to  be  increased 
immediately,  but  that  of  the  carbonaceous  substances 
is  evident.  Muscular  exercise  does  not  increase  the  quan- 
tity of  excreted  urea,  but  it  augments  that  of  the  carbonic 
acid  exhaled  to  perhaps  tenfold  the  amount  excreted  in 
rest  during  equal  times.     The  muscle  participates  in  all 
febrile  diseases  of  the  body,  and  is  frequently  the  seat 
of  idiopathic  processes.     In  typhoid  and  typhus  fever 
it  becomes  disorganised  in  a  high  degree,  losing  struc- 
ture, and   assuming   a   yellow   appearance.     In   fatty 
degeneration  it  loses  its  contractility,  and  shows  fat 
in  a  free  state  amongst  changed  structure  elements. 
In  death  from  carbonic  oxyde  it  has  a  red  florid  colour 
due  to  the  combination  of  the  poison  with  its  hemato- 
crystalline ;  in  tetanus  it  is  spasmodically  contracted, 
changed,  and  frequently  torn ;   in  hydrophobia   it   is 
similarly  injured   and   torn ;    in  trichiniasis  it   is  the 
specific  seat  of  a  parasite,  the  trichina  spiralis,  which 
does  not  live  in  any  other  tissue.     The  changes  of  the 
muscles  in  diseases  have  only  just  begun  to  be  studied, 
and  cannot  fail  to  be  found  of  the  utmost  importance. 
As  the  muscle  during  life  takes  up  oxygen  from  the  Dead  muscle. 
blood,  besides  nutriment  of  the  most  varied  kind,  and 
renders  back  to  the  venous  blood  carbonic  acid,  water, 
and  a  host  of  refuse  matters,  so  does  the  dead  muscle, 
its  coagulated  myosine  notwithstanding,  continue  some 
time  to  breathe,  take  up  oxygen  and  give  out  carbonic 
acid.     At  last  its  atoms   take   a   new  direction,   and 


40  CHEMICAL   PHYSIOLOGY. 

physiolysis  or  putrefaction  commences.  The  muscle 
yields  the  products  common  to  the  albuminous  sub- 
stances, tyrosine,  leucine,  volatile  acids,  and  alkalies, 
&c.  The  same  products  are  obtained  by  chemolysis  ; 
leucine  was  first  discovered  (by  Braconnot)  in  the 
decomposed  muscular  tissue.  By  continuing  the  study 
of  chemolysis  we  shall  probably  be  able  to  learn  more 
about  the  changes  of  the  muscles  in  disease,  as  well  as 
about  the  ingredients  of  flesh  extracts  which  are  at 
present  unknown. 
involuntary  The  smooth  or  organic  involuntary  muscular  fibres 

muscles.  » 

contain  some  ingredients  similar  to  those  of  the 
striated,  but  require  to  be  better  studied  —  a  matter  of 
great  difficulty,  as  they  cannot  easily  be  isolated. 
ingredients  The  nerves  and  brain  consist  mainly  of  minutely 
fafo  \ong  fibres,  and  of  cells  standing  in  connection 
with  these  fibres.  These  fibres  are  membranous  tubes, 
filled  with  a  peculiar  nerve  or  brain  marrow.  When 
the  nerves  are  taken  out  of  the  living  body  they  change 
quickly,  and  the  marrow  of  the  tubes  separates  into 
two  substances  —  a  central  one,  the  cylinder  axis,  and 
an  outer  or  periaxial  portion.  This  change  is  not  yet 
quite  explained.  Possibly  it  may  consist  in  a  coagula- 
tion of  the  axial  cylinder,  which  causes  its  contraction. 
The  axial  cylinder  is,  however,  already  in  life  of  a 
different  chemical  composition  from  the  periaxial  tube, 
for  it  shows  no  effects  in  the  polariscope,  while  the 
periaxial  part  exhibits  dark  or  light  crosses.  The 
chemical  constitution  of  these  matters  is  perhaps  the 
greatest  problem  of  organic  and  physiological  chemistry. 
A  consideration  of  all  researches  since  the  time  of 


of  the  brain 

and  nerves. 


CHEMICAL    PHYSIOLOGY.  41 

Vauquelin  tends  to  show  that  brain  matter  is  con- 
stituted similarly  to  the  hematocrystalline  of  the  blood ; 
that  it  contains  an  albuminous  matter  to  which  is 
combined  a  substance  containing  nitrogen  and  phos- 
phorus ;  that  its  molecule  must  therefore  be  very  com- 
plicated and  large,  and  that  the  matters  hitherto  ex- 
tracted from  the  brain  are  at  the  most  detached 
proximate  nuclei,  or  single  stones  broken  out  of  the 
mosaic  picture  which  its  molecule  may  be  imagined  to 
represent.  The  principal  one  of  these  detached  nuclei 
is  a  body  of  which  a  small  quantity  can  be  extracted 
from  brain  matter  by  boiling  alcohol,  and  which  has 
been  variously  termed  brain-wax,  brain-fat;  but  by  Brain-fat, 

**  **       nuvoliiMtui 


Fremy,  who  first  obtained  it  pure  and  determined  its  cerebric  acid- 


cerebrine, 

cerebric 

protagon 

composition,  was  found  to  be  an  acid,  and  termed 
cerebric  acid.  Lately  Liebreich,  having  examined  the 
same  substance,  gave  it  the  name  of  protagon,  but 
without  any  valid  reason.  This  cerebric  acid  appears 
in  crystalline  needles,  and  gives  remarkable  reactions. 
By  decomposition  it  yields  fatty  acids,  glycero-phos-  ratty  add, 
phoric  acid  (C3H9P06)  containing  the  whole  of  its 
phosphorus,  neurine  (C5H13ISF),  choline  (C5H15N"02), 
and  cerebrine  (C17H33N03).  This  reaction  makes  it 
probable  that  it  is  proximately  composed  of  cerebrine 
and  lecythine  (C43H84NP09),  which  latter  yields  the 
products  last  mentioned  by  the  following  reaction; 


Lecythine. 

C3H9P0 

Glycero-  Choline.  Oleic  acid.      Margaric  acid. 

phosphoric  acid. 


42  CHEMICAL    PHYSIOLOGY. 

Much,  of  it  is  contained  in  the  brain  in  a  state  of  such 
firm  combination  that  even  concentrated  sulphuric  acid 
does  not  easily  set  it  free.  There  is  further  in  the  brain 
cholesterme,  the  peculiar  alcohol  of  which  a  quantity 
is  constantly  excreted  with  the  bile.  The  albuminous 
substance  of  the  brain  has  not  yet  been  isolated  com- 
pletely ;  a  small  quantity  can  be  extracted  as  potash- 
mfooiisinat""  albumen  (or  caseine) ;  another  quantity  is  insoluble  in 
water,  and  its  presence  can  only  be  deduced  from  the 
curdling  of  brain-matter  by  boiling,  and 'from  the  pro- 
ducts of  the  chemolytic  process,  which,  as  I  have  found 
by  special  researches,  yields  all  the  products  of  chemo- 
lysis  of  albuminous  matter,  volatile  acids  and  alkalies, 
leucine,  tyrosine,  and  other  substances.  Of  other 

Various  in-  J 

gredients.  matters  there  are  found  in  the  brain  substance  lactic 
and  a  volatile  acid,  and  inosite;  uric  acid,  xanthine 
and  hypoxanthine ;  kreatine.  Sugar  is  sometimes 
found,  but  may  be  merely  a  product  of  transformation 
of  cerebrine,  and  more  rarely  a  substance  which  gives 
reactions  similar  to  starch,  and  the  study  of  which 
may  perhaps  throw  some  light  on  the  peculiar  disease 
termed  amyloid  degeneration.  In  diseases,  leucine  and 
a  homologue  of  it  appear  sometimes.  In  others  much 
urea  collects  in  the  brain  and  in  the  cerebro-spinal 
fluid,  which  fills  the  cavities  of  the  brain  and  spinal 
marrow.  The  largest  quantities  of  urea  are  met  with 
in  cholera,  in  which  the  cerebro-spinal  fluid  may  con- 
tain as  much  as  ordinary  urine.  In  a  case  of  softening 
of  the  brain  Lehmann  found  glycero-phosphoric  acid 
in  the  softened  matter.  The  brain  substance  con- 
tains 25  per  cent,  of  solids  only,  and  75  per  cent. 


CHEMICAL   PHYSIOLOGY.  43 

of  water.  Its  ash  contains  acid  phosphates  and  a 
quantity  of  free  phosphoric  acid,  a  residue  of  the 
destroyed  cerebric  acid.  Besides  much  potassium, 
some  sodium,  little  magnesium  and  calcium,  the  ash 
always  contains  a  notable  quantity  of  iron.  The  ash 
of  the  grey  matter  of  the  brain  is  always  alkaline, 
owing  in  part  to  the  circumstance  that  it  contains  less 
cerebric  acid  than  the  white  matter.  When  an  ethereal 
extract  of  brain  matter  is  mixed  with  water,  and  seen 
under  the  microscope,  it  swells  and  projects  various 
peculiar  forms  of  matter  in  various  directions.  The 
phenomenon  is  due  to  cerebric  acid,  which  is  dissolved 
in  soap ;  it  has  given  much  and  varied  amusement  to 
microscopists. 

The  connective  tissue  forms  tendons,  fasciao  org™™ctive 
envelopes  of  muscles  and  limbs,  ligaments  of  joints  and 
capsules,  and  binds  all  organs  of  the  body  together. 
It  consists  of  fibres,  of  a  cement  uniting  these  to  a 
tissue,  of  cells  or  so-called  corpuscles,  and  is  inter- 
spersed with  elastic  fibres.  It  is  soaked  with  potas- 
sium-albumen. The  cement  is  soluble  in  caustic  lime  Cement 
and  in  baryta-water ;  it  is  reprecipitated  by  acetic  acid, 
and  then  manifests  itself  as  mucine,  identical  with  that 
of  the  salivary  glands  and  embryonic  tissues,  e.  g.,  the 
umbilical  cord ;  the  fibrillas  remain  isolated,  but  mixed 
with  the  corpuscles  or  cells  and  their  nuclei,  and  with 
elastic  fibres.  In  acetic  acid  the  fibrillse  are  trans- 
formed into  glutine  or  glue.  The  same  transformation 
is  effected  by  prolonged  boiling  in  water.  The  elastic 
fibres  resist  this  treatment.  Both  sorts  of  fibre  by 
chemolysis  yield  tyrosine,  leucine,  volatile  acids,  and 


44  CHEMICAL   PHYSIOLOGY. 

alkalies,  but  the  gelatine  is  distinguished  by  yielding 
glykokoll,  the  lower  homologue  of  leucine,  while  elastic 
fibres  yield  more  leucine.  Mucine  yields  sugar  by 
chemolysis,  and  in  this  respect  resembles  chondrine, 
but  it  also  yields  much  tyrosine,  up  to  7  per  cent. 
These  various  data  have  given  rise  to  the  idea  that 
mucine  and  glutine  were  products  of  a  peculiar  cleavage 
of  albumen,  but  albumen  has  not  yet  been  found  to 
yield  any  sugar.  The  cells  or  corpuscles  of  the  con- 
nective tissue  consist  of  a  semi-fluid  matter  which  is 
termed  the  protoplasma,  and  of  nuclei.  In  the  pro- 
toplasma  of  the  cells  of  the  connective  tissue  pigment 
is  frequently  deposited  (choroid,  rete  Malpighii  of 
negro, bronzed  skin  disease,  freckles,  melanotic  cancers), 
which  is  black  or  brown.  Of  this  pigment  very  little 
is  known. 

Fatty  tissue.  The  fat  tissue  is  made  up  of  cells,  in  the  interior  of 
which  fat  is  deposited,  and  of  connective  tissue.  The 
fat  cells  are  probably  peculiar  organs,  but  the  cells  of 
the  connective  tissue  above  described  are  probably  able 
to  deposit  fat  within  their  substance  under  certain 
circumstances.  Some  fat  tissue  remains  permanently 
in  the  body,  some  may  lose  its  fat  during  starvation  or 
disease,  and  regain  it  afterwards.  The  fats  in  the  human 
fat  tissue  are  mostly  those  described  in  the  paragraph  on 
digestion,  namely,  tri-stearine,  tri-palmitine,  tri-oleine. 
The  fatty  tissue  is  subject  to  hypertrophy,  or  excessive 
infiltration;  there  are  also  peculiar  colorations  ob- 
served in  several  diseases,  (e.  </.,  consumption  or 
phthisis),  which  are  due  to  an  accumulation  of  luteine. 
Newly  formed  fat  tissue  is  observed  in  the  fatty 


CHEMICAL   PHYSIOLOGY.  45 

tumours  or  lipomata.  Fat  in  tissue  may  originate  in 
several  ways  ;  it  may  have  been  eaten  with  the  food, 
and  after  absorption  have  only  been  carried  to  the  cells ; 
orit  may  be  formed  from  sugar,  dextrine,  and  glykogen  ; 
or  lastly,  it  may  owe  its  existence  to  the  decomposition 
of  albumen.  Thus  the  cholic  acid  of  bile  might  easily 
yield  any  of  the  fatty  acids,  and  sugar  the  glycerine. 
But  the  proofs  of  any  of  these  processes  have  not  yet 
been  furnished. 

Cartilage  contains  peculiar  cells  and  chondrinogen,  cartilage. 
or  a  substance  which  by  boiling  becomes  chondrine. 
This  matter  gelatinises  like  gelatine,  but  is  not  soluble 
in  acetic  acid,  on  the  contrary  is  precipitated  by  it. 
Boiled  with  hydrochloric  acid,  chondrine  yields  sugar. 

The  chemical  composition  of  the  cornea  is  similar  to  Comea. 
that  of  cartilage,  particularly  the  hyaline  variety. 

The  fluids  of  the  eye,  particularly  the  vitreous  body, 
contain  much  potassium  chloride  and  little  organic 
matter. 

The  cartilages  are  subject  to  a  degeneration  which  ossification. 
terminates  in  ossification. 

The  cartilage  surfaces  of  joints  are  lubricated  by  a  synovia. 
fluid  which  is  termed  synovia.  It  contains  about  94 
per  cent,  of  water,  3 '5  of  albumen,  0*5  of  mucine,  and 
more  than  1  per  cent,  of  ash.  Its  origin  is  not  yet 
satisfactorily  explained.  During  diseased  conditions 
of  joints  much  synovia  can  be  detected  ;  the  collection 
of  excess  of  synovia  in  a  joint  constitutes  hydrarthron.  Hydrarthro 

A  matter  similar  to  chondrinogen  is  hyaline,  of  which  Hyaline. 
the  cysts  of  old  echinococci  are  composed.      Boiled 
with  dilute  sulphuric  acid  it  yields,  like  the  chitine  of 


46  CHEMICAL    PHYSIOLOGY. 

insects  and  articulate  animals  (C9H15N06)  dextrose 
fermentescible  sugar. 

Bones.  The   bones   consist   of  a   peculiar    combination    of 

organic  matter  with  mineral  earthy  phosphates, 
and  contain  as  accessory  matters  marrow,  blood- 
vessels, and  cellular  nuclei  in  the  cavities  called  bone- 
corpuscles. 

osseine.  The  organic  substratum  is  called  osseine  (a  name 

which  it  would  be  better  to  apply  to  the  entire  bone 
tissue),  the  mineral  matters  are  termed  bone-earth. 
The  osseine  is  obtained  by  extracting  the  bone-earth 
with  dilute  hydrochloric  acid.  It  retains  the  structure 
of  the  bone  substance,  which  is  disposed  in  concentric 
layers  round  a  tubular  centre.  Osseine  dissolves  on 
boiling  in  water  like  glutin,  but  differs  from  the  latter 
in  several  particulars,  although  the  product  of  the 
solution  in  hot  water  is  true  gelatine.  Of  osseine 
purified  bones  contain  from  29'5  to  30'9  per  cent.,  with 
which  68'3  to  69*4  per  cent,  of  earthy  salts  are  in  com- 
bination. The  regularity  of  these  proportions  has  led 
to  the  assumption  that  bone  is  a  chemical  compound  in 
definite  atomic  proportions  of  osseine  and  earths,  and 
not  merely  a  tissue  in  which  earths  are  deposited. 
Some  remarkable  experiments  show  that  gelatine  and 
earthy  phosphates  have  a  peculiar  attraction  for  each 
other.  Thus  a  mixture  of  gelatine  and  bone-earth  in 
hydrochloric  acid,  when  neutralised  by  ammonia, 
deposits  bone-earth  with  20  per  cent,  of  gelatine ; 
vice  versa  when  tannic  acid  is  added  to  such  a  solution 
tannate  of  gelatine  with  much  bone-earth  is  precipi- 
tated. Bone-earth  contains  9*1  per  cent,  of  calcium 


CHEMICAL   PHYSIOLOGY.  47 

carbonate,  87' 7  of  calcium  phosphate  (Ca3Po06),  1/7  of 
magnesium  phosphate  (Mg3P206),  and  3  per  cent,  of 
calcium  fluoride  (CaF2).  The  nutrition  of  the  bones 
proceeds  from  their  surface  towards  their  cavities. 
Certain  dyes,  given  with  the  food,  penetrate  into  the 
bones  and  stain  them.  The  idea  formerly  combined 
with  this  experiment,  namely,  that  the  bone  was 
rapidly  renewed  from  without  and  absorbed  ^in  the 
marrow  cavity,  is  probably  quite  untenable.  In 
several  important  diseases  the  bones  are  greatly 
affected,  and  become  either  brittle,  or  soft  and  bend. 
Such  diseases  are  rhachitis,  or  rickets,  common  in 
children,  the  osteomalacia  of  pregnant  women,  and Osteomalacia- 
that  particular  form  which  attacks  aged  persons.  In 
these  diseases  the  bone-earth  falls  to  about  30  per 
cent,  of  the  dry  bones,  while  the  osseine  rises  to  60 
and  80  per  cent.  The  osseine  at  the  same  time 
changes  its  chemical  character,  by  a  curious  tissue 
transformation,  starting  from  the  marrow  cavities,  and 
now  no  longer  yields  glutine.  It  seems  that  the  agent 
by  means  of  which  in  this  no  doubt  complicated 
process  the  earths  are  removed  is  lactic  acid,  which  Jj^ acid  in 
under  these  circumstances,  and  not  in  health,  is  found 
in  and  about  the  bones.  These  diseases  urgently  call 
for  chemical  investigation. 

The  teeth  are  bones,  of  which  a  part,  the  root,  is  con-  Teeth. 
structed  like  ordinary  bone ;  while  the  top  or  crown  is 
formed  upon  a  particular  plan,   round  many   minute 
tubes  ;  this  latter  tissue  is  termed  dentine.     The  outer  Dentine. 
hard  covering,  the  cement,  is  an  epithelial  formation,  cement, 
containing  only  4  per  cent,  of  organic  matter,  92  per 


48  CHEMICAL    PHYSIOLOGY. 

cent,  of  earthy  phosphates,  and  4  per  cent,  calcium 
fluoride. 

PUS.  Pus  is  a  product  of  disease  or  injury.  It  consists  of 

a  serum,  in  which  many  corpuscles,  resembling  the 
white  corpuscles  of  the  blood,  are  suspended.  From 

?Spusncieln  the  corpuscles,  separated  by  filtration,  myosine  (see 
muscles)  is  obtained.  This  substance  is  probably  the 
instrument  of  the  contractility  of  these  bodies.  The 

paragiobu-    serum  has  fibrino-plastic  properties,  i.e.,  contains  para- 

line,  caseine, 

globuline,  which  can  be  precipitated  by  carbonic  acid  ; 
on  addition  to  the  filtrate  of  acetic  acid  potassium  albu- 
minatejDr  caseine  is  precipitated,  and  after  the  removal  of 
this  latter  serum  albumen  is  precipitated  by  heating. 
Mucine  has  never  been  found  in  pus.  Chondrine  and 
glutine  have  been  found  in  the  filtrate  from  the  pus 
coagulated  by  boiling.  They  are  probably  connected 
with  the  corpuscles,  like  the  glutine  which  is  found  in 
the  blood  in  leukocythsemia.  Pus,  probably  in  its  cor- 
.  puscles,  contains  cerebric  acid  and  cholesterine  ;  the 

Cholesterine.  r 

latter  is  deposited  on  standing.  During  standing  and 
decomposition  pus  also  deposits  palmitic  and  stearic 
acid  in  crystals,  oleic  acid  after  addition  of  acetic  acid. 
i'atty  adds.  QOod  or  healthy  pus  from  wounds  contains  no  volatile 
volatile  fatty  acids,  but  decomposing  pus  yields  volatile  acids  of  the 
fatty  series,  formic,  butyric,  valerianic,  in  short  —  pro- 
ducts of  putrefaction.  Pus  from  abscesses,  from 
phosphorus  disease,  and  ulcerating  cancers,  contains 
an  acid,  which  as  it  gives  a  rose-pink  reaction  with 
chlorine  water,  has  been  termed  chlorrhodinic  acid. 
A  similar  substance  can  be  obtained  from  decomposing 
pancreas  extract  and  lymphatic  glands.  Pus  may  con- 


CHEMICAL    PHYSIOLOGY.  49 

tain  leucine,  tyrosine,  xanthine,  and  uric  acid ;  in  the 
pus  from  jaundiced  persons  biliary  acids  and  cholo- 
phseine  are  found ;  in  that  from  diabetic  patients  sugar. 
The  so-called  blue  pus  derives  that  colour  from  a  kind 
of  vibrio,  which  yields  its  pigment  to  chloroform,  from 
which  it  is  obtained  in  crystals,  and  termed  pyocyanine. 
The  solid  matters  contained  in  pus  amount  to  from 
10  to  15  per  cent. ;  its  ash  is  similar  to  that  of  blood, 
contains  72  per  cent,  of  sodium-chloride,  and  more 
potassium-salt  than  blood-serum.  A  knowledge  of  the 
composition  and  products  of  decomposition  of  various 
kinds  of  pus  from  abscesses,  ulcers,  wounds,  &c.,  is  of 
the  utmost  importance  for  the  study  and  treatment  of 
reactive  fever  after  wounds  and  operations,  of  various 
forms  of  blood  disease  termed  septichsemia,  and  pysemia. 
In  all  these  affections  pus,  or  products  of  its  decompo- 
sition, are  absorbed  or  enter  in  a  more  grossly  me- 
chanical manner  into  the  lymph  and  blood,  set  up  an 
acute  patholytical  process  which  leads  to  violent  attacks 
of  shivering,  fevers,  sweating,  diarrhoea ;  then,  in  the 
case  of  septichaemia  and  pyaemia  to  secondary  deposits 
of  pus  or  other  fluids  in  various  organs  and  cavities, 
particularly  the  lungs  and  liver,  and  ultimately,  and  in 
nearly  all  cases,  to  death.  Against  this  fatal  disease  a 
particular  kind  of  treatment  of  wounds,  the  so-called 
antiseptic  treatment,  has  lately  been  devised,  and  is  now 
under  the  consideration  of  surgeons. 

The  function  of  the  spleen  is   not  well  known,  but  spleen 
seems    connected    with    the    elaboration    of    certain 
constituents   of   the  blood  and    certain    processes  of 
digestion.      The   organ   contains  much  blood,   and  a 

4 


50  CHEMICAL    PHYSIOLOGY. 

separation  of  its  tissue  and  juice  from  its  blood  has  not 
yet  been  effected.  The  fresh  spleen  is  alkaline,  but 
soon  becomes  acid.  The  watery  extract  contains 
hematocrystalline  and  the  other  ingredients  of  blood, 
besides  a  peculiar  albuminous  matter  which  on 
combustion  leaves  phosphoric  acid  and  iron  oxyde.  It 
encloses  some  cholesterine.  After  removal  of  all 
albuminous  matters  there  are  in  the  extract  of  fixed 
acids  the  lactic  and  succinic,  of  urinary  products 
hypoxanthine,  xanthine,  and  uric  acid,  of  volatile  fatty 
acids  formic,  acetic,  butyric,  of  amido-acids  leucine  ;  of 
alcohols  there  is  inosite  in  considerable  quantity. 
These  ingredients  show  that  chemical  processes  of 
various  kinds  must  be  carried  on  actively  in  the  spleen. 
They  are,  however,  not  indispensable  to  life,  as  animals 
from  which  the  spleen  has  been  removed  by  operation 
continue  to  live  without  any  perceptible  disturbance. 
In  leukocythaemia  the  spleen  is  frequently  very  large, 
and  weighs  up  to  nine  and  ten  pounds.  If  it  be  found 
small  in  that  disease  the  lymphatic  glands  are  certainly 
w-.xy  dege-  enlarge^.  The  spleen  is  sometimes  subject  to  (here) 
spiSr  °  miscalled  amyloid  degeneration.  Although  in  this  state 
it  gives  many  reactions  of  albumen  it  is  indiges- 
tible in  artificial  gastric  juice;  it  gives  no  sugar  by 
treatment  with  sulphuric  acid,  and  is  little  prone  to 
change  by  artificial  or  natural  influences. 

Thynms  The  thymus  gland  is  a  mysterious  organ  situated  in 

the  chest  in  front  of  the  lungs.  It  becomes  of  less 
importance  to  the  adult  than  it  probably  is  to  the  foetus 
in  the  womb.  It  contains  albumen,  collagene,  elastic 
tissue,  a  little  fat,  leucine,  xanthine,  hypoxanthine, 


CHEMICAL   PHYSIOLOGY.  51 

succinic  and  lactic  acid,  and  perhaps  also  volatile  fatty 
acids  and  sugar.  In  the  progress  of  the  involution  of 
the  thymus  the  amount  of  sodium  contained  in  it  is 
nearly  doubled. 

The  thyroid  contains  nearly  the  same  chemical  con- Thyroid 
stituents  as  the  thymus.  It  would  be  very  confusing 
that  the  constituents  of  glands  of  the  most  varied 
connection  and  situation  are  identical,  were  we  not 
reminded  that  the  denned  ingredients  are  perhaps  only 
one  fourth  or  one  sixth  of  the  whole  of  the  ingre- 
dients, and  that  specific  differences  may  therefore  be 
discovered  upon  the  ingredients  which  at  present  are 
undefined.  The  thyroid  is  said  to  contain  mucine,  par- 
ticularly when  in  the  state  termed  colloid  degeneration  ; 
it  then  also  contains  cholesterine .  When  containing 
brown  fluids,  in  the  disease  termed  struma,  a  sediment 
of  blood-corpuscles  is  mostly  present,  which,  however, 
contain  only  decomposed  hematocrystalline  in  the  form 
of  hematine. 

The  renculi  yield  many  curious  coloured  reactions. 
Their  alcoholic  or  ethereal  extracts  become  yellow  and 
red  when  exposed  to  the  air,  and  show  a  green  fluor- 
escence due  to  renculine ;  their  watery  extracts  are 
coloured  red  by  iodine,  and  blackish  blue  by  iron- 
chloride.  They  contain  leucine,  but  the  presence  of 
other  particular  biliary  matters  which  has  been  alleged 
is  at  present  not  proved.  In  certain  chronic  diseases 
(Addison's  disease,  or  bronzed  skin),  in  which  the 
skin  is  more  or  less  copper  or  brown-coloured,  the 
suprarenal  capsules  are  specifically  diseased. 

The  ovaries  are  composed  of  the  stroma,  the  Graafian 


52  CHEMICAL    PHYSIOLOGY. 


Ovaries. 


follicles  and  the  corpora  lutea.  The  latter  contain 
fluid  and  coagulable  serum,  particularly  while  they 
possess  an  internal  cavity.  In  their  substance  is  depo- 
sited in  granules  luteine,  a  yellow  matter  soluble  in 
alcohol,  ether,  and  chloroform,  and  distinguished  by 
three  absorption-bands  which  its  solutions  show  in  the 
blue  and  violet  part  of  the  spectrum.  A  similar  yellow 
matter  is  contained  in  the  yelk  of  eggs.  The  yellow 
colour  of  corpora  lutea  is  not  due  to  hematine  as  has 
hitherto  been  generally  assumed. 

In  some  forms  of  ovarian  cyst  a  yellow  albuminous 
fluid  is  contained,  which  shows  the  spectrum  of  luteine 
without  any  preparation  ;  in  this  morbid  fluid  the  luteine 
(cysto-luteine)  is  therefore  contained  in  solution,  while 
in  the  normal  corpora  lutea  it  is  contained  in  granules 
(o  vario-luteine) . 
giSd?  The  salivary  glands  contain  mucine  and  leucine, 

xan  thine  and  hypoxan thine. 

Pancreas.          The  pancreas  contains  much  leucine,  a  homologue  of 
it,  xanthine,  hypoxanthine,  and  guanine.     Also  some  of 
the  ferments  mentioned  in  the  paragraph  on  digestion 
can  be  extracted  from  its  pulp  as  well  as  from  its  juice. 
Liver.  The  liver  consists  of  cells,  which  are  the  main  seats  of 

its  specific  function,  and  of  blood-vessels  and  bile  ducts, 
interspersed  with  lymph  vessels  and  nerves.  The  blood 
can  be  washed  out  by  water.  The  cells  are  made  up  of 
a  protoplasma,  which  may  contain  as  visible  ingredients 
fat  in  large  and  small  granules,  cholophaeine  in  small 
red  granules,  nuclei,  with  one  or  two  corpuscles,  and 
as  invisible  ingredients  demonstrable  by  experiment 
only,  a  coagulable  matter  which  sets  soon  after  death, 


CHEMICAL   PHYSIOLOGY.  53 

albumen,  mucine,  and  glykogen.  Sugar  and  biliary 
acids  are  also  always  obtained  from  the  extract  of  the 
liver,  although  the  ducts  may  have  been  carefully 
washed  out ;  and  as  cholophaeine  is  contained  in  the 
cells,  we  may  assume  that  the  bile  acids  are  also  con- 
tained and  made  in  the  cells.  The  fresh  liver  is  always 
alkaline,  but  on  standing  it  becomes  acid.  The  gly- 
kogen  is  mostly  or  entirely  transformed  into  sugar. 
The  liver-extract  made  by  boiling  water  mostly  con- 
tains lactic  acid  and  volatile  fatty  acids,  inosite, 
hypoxanthine,  xanthine,  and  uric  acid,  and  leucine. 
The  latter  body  occurs  in  livers  which  are  quite  fresh, 
in  very  small  quantity,  but  increases  by  decomposition, 
for  which  the  tissue  of  the  liver  or  its  cells  possess 
particular  aptitude.  Fat  is  extracted  from  most  livers, 
in  large  quantities  from  diseased  livers.  Tyrosine 
occurs  in  diseased  livers  only,  and  is  not  easily  obtained 
even  from  thoroughly  putrid  livers.  In  the  ash  of  the 
liver  phosphoric  acid  and  potassium  predominate,  which 
is  the  more  to  be  noted  as  the  bile  acids  in  man  are 
mainly  combined  with  sodium.  From  fresh  livers  of 
young  persons  and  animals  hydrogen  is  sometimes 
evolved  on  immersion  in  warm  water.  The  degene-  Bacony  liver 
ration  of  the  liver,  which  is  sometimes  wrongly  called 
amyloid,  or  otherwise  the  "  Speckleber "  of  the  Ger- 
mans, and'"  waxy  degeneration  "  of  the  English,  has 
not  any  resemblance  to  the  amyloid  degeneration  of 
the  spinal  marrow  :  for  iodine  and  sulphuric  acid,  or 
iodine  alone,  produce  in  it  only  a  red  or  reddish-brown 
.mahogany-like  coloration,  its  material  being  evidently 
}f  an  albuminous  kind  :  and  on  extraction  by  alcohol 


54  CHEMICAL    PHYSIOLOGY. 

and  ether,  I  have  found  in  it  considerable  quantities 
of  cholesterine,  fat,  and%paralbuinen,  but  neither  bile 
nor  sugar.  Having  during  many  years,  and  in  many 
cases,  observed  considerable  quantities  of  leucine  in  the 
liver,  and  having  frequently  experienced  great  difficulty 
in  isolating  this  substance,  and  separating  it  from  others, 
I  subjected  to  a  special  study  the  compounds  of  leucine 
with  metals,  and  discovered  a  new  copper  compound 
which  renders  leucine  entirely  insoluble  in  water  and 
neutral  fluids.  For  the  extraction  of  hypoxanthine  and 
xan thine  I  have  also  devised  special  processes. 

Kidneys.  rj^g  kidneys  contain  much  blood,  collagene  fibres,  and 

some  fat ;  to  water  extraction  they  yield  chlorrhodinic 
acid,  uric  acid,  and  bodies  resembling  hypoxanthine 
and  xanthine,  but  urea  is  scarcely  obtainable  from  them. 
Cystine  and  inosite  have  on  some  rare  occasions  been 
met  with.  The  chemical  changes  of  the  kidneys  in 
diseases  have  not  yet  been  sufficiently  examined. 

The  urine.  The  urine  is  the  secretion  of  the  kidneys.  It  is  the 
lixiviated  refuse  from  the  chemical  processes  of  the 
body.  It  contains  a  yellow  colouring  matter,  urochrome, 
which  by  chemolysis  yields  various  remarkable  products 
of  decomposition.  The  first  is  uromelanine,  C36H43N7010, 
a  most  interesting  substance,  with  an  atomic 
weight  of  733,  being  one  of  the  highest  at  present 
established  in  organic  chemistry.  Accompanying 
uromelanine  there  is  a  small  quantity  of  a  matter  which 
by  treatment  with  sulphuric  acid  yields  the  reaction  and 
spectrum  of  cruentine,  termed  paramelanine.  The 
next  product  is  uropittine,  not  as  yet  sufficiently  studied. 


CHEMICAL    PHYSIOLOGY.  55 

Then  there  is  omicholine,  empirical  formula  C33H38N05,  omi 
an  organic  base  with  fluorescent  properties  and  a 
peculiar  spectrum,  and  omicholic  acid,  C15H33N04,  also 
fluorescent,  but  slightly  differing  in  its  spectrum  and 
composition  from  omicholine  ;  further,  acetic  and  formic 
acid.  From  these  products  it  is  evident  that  urochrome 
must  possess  a  very  high  atomic  weight ;  it  may,  per- 
haps, be  a  derivate  of  hematocrystalline ;  uromelanine  no 
doubt  represents  the  nucleus  of  hematine.  The 
ingredient  which  occurs  in  urine  in  the  largest  quantity 
is  urea,  CH4N30,  of  which  a  man  secretes  about  30  Urea. 
grammes  in  twenty-four  hours.  Then  there  is  kreati- 
nine  C4H7N~30,  the  same  as  that  which  occurs  in  the 
muscles.  It  is  partly  changed  into  kreatine,  C4H9N303, 
by  taking  up  an  atom  of  water  during  the  process  of 
preparation.  From  kreatinine  is  derived  sarkosine,  sarkosm 
which  is  isomeric,  or  perhaps  identical  with  alanine 
CoELNOo.  There  is  further  contained  in  urine  uric  acid,  Uric  :ici<1 

o       /  '  group. 

C5H4N403,  which  may  form  calculi  and  cause  much 
trouble,  and  a  series  of  bodies  being  less  oxydised  than 
uric  acid,  namely,  guanine,  C5H5N50,  hypoxanthine, 
CgHJS^O,  and  xanthine,  C5H4N403.  Further,  there  is 
an  acid  which  from  having  been  first  discovered  in 
horses'  urine  is  termed  hippuric,  C9H9N03,  remarkable  ; 
by  its  consisting  of  a  combination  of  glykokoll  C3H5N03, 
and  benzoic  acid,  C7H603,  less  an  atom  of  water,  H3O, 
and  by  its  being  formed  in  considerable  quantity 
in  the  human  body  when  benzoic  acid  is  being 
taken,  or  greengages  are  consumed.  The  extractives 
are  at  least  three  in  number;  of  these  I  have  fully 
identified  kryptophanic  acid  which  if  considered 


56  CHEMICAL    PHYSIOLOGY. 

as  dibasic  has  the  formula  C5H9N05,  but  which  must 
perhaps  be  considered  as  tetrabasic,  and  then  has  the 
formula  C10H1SN3010 ;  in  that  case  its  metallic  salts  will 
have  the  general  formula  C10H14M4N3010.  Another 
extractive  acid  is  paraphanic  acid,  CnH18N~206,  dibasic. 
Under  some  circumstances  allantoine  appears,  C4H6N03, 
which  can  also  be  produced  from  uric  acid  artificially, 
along  with  other  remarkable  products.  Of  inorganic 

Salts-  salts  the  phosphates  of  lime  and  magnesia,  and  of 
potash,  and  potassium  chloride,  are  present  in  consider- 
able quantity,  but  most  prevalent  is  the  sodium-chloride 
or  common  salt.  Of  some  matters  minute  traces  appear 

Sol  in  the  urine,  thus  of  sugar  and  of  alcohol,  after  these 
bodies  have  been  taken  by  deglutition.  In  diseases 

inS-edS1  there  may  appear  blood,  albumen,  fibrine  (paraglobuline 
and  fibrino-plastic  matter),  fatty  acids  and  fats,  large 
quantities  of  sugar,  as  in  diabetes,  leucine,  tyrosine, 
abnormal  colourless  matters  yielding  by  acids  uro- 
cyanine  and  urorubine,  as  in  cholera ;  oxalic  acid  and 
oxalate  of  lime,  as  in  a  particular  disease  which  frequently 
ends  in  the  formation  of  calculi.  Much  as  the  urine 
has  been  studied  its  chemistry  is  by  no  means  accom- 
plished, and  on  the  causes  of  the  most  troublesome 
diseases  showing  themselves  by  symptoms  in  the  urine, 
gout,  uric  acid  calculus,  oxalic  diathesis,  diabetes,  chy- 
lous  urine,  our  knowledge  is  as  yet  very  incomplete. 

Under  all  circumstances,  however,  the  analysis  of 
the  urine  is  an  indispensable  aid  to  clinical  diagnosis, 
and  furnishes  most  valuable  positive  and  negative 
information  on  acute  as  well  as  chronic  diseases. 

s«eat.  The  secretion  of  the  skin,  discharged  in  large  quan- 


CHEMICAL   PHYSIOLOGY.  57 

titles  after  exertion  or  under  the  influence  of  a 
heated  atmosphere,  contains  much  surface  epithelium. 
Of  chemical  ingredients  there  are  observed  lactic  and 
sudoric  acid,  the  latter  peculiar  to  sweat  and  not  found 
anywhere  else,  and  urea.  There  is  much  sodium-chloride, 
little  or  no  phosphate.  Sometimes  volatile  fatty  acids,  e.g. 
valerianic,  are  found  in  small  quantity,  but  it  is  possible 
that  they  are  formed  after  the  sweat  has  been  secreted. 

In  respiration  oxygen  of  the  air  inhaled  together  with  Breath 
its  nitrogen  is  absorbed  by  the  blood,  and  in  exchange 
carbonic  acid  and  water  are  given  out.  The  expired 
air  therefore  contains  less  oxygen  than  the  inspired,  and 
a  quantity  of  carbonic  acid  instead.  But  the  whole  of 
the  oxygen  inhaled  does  not  return  as  carbonic  acid 
and  water  ;  a  portion  is  otherwise  combined  and  leaves 
the  body  in  the  urinary  products  of  oxydation,  parti- 
cularly urea.  A  healthy  strong  man  exhales  in  twenty- 
four  hours  upwards  of  400  litres  of  carbonic  acid,  and 
inhales  upwards  of  500  litres  of  oxygen.  The  expired 
air  during  rest  contains  about  four  volumes  per  cent,  of 
carbonic  acid.  During  activity  the  expiration  of  car- 
bonic acid  becomes  much  more  rapid,  and  in  extreme 
cases  may  for  a  short  time  rise  to  tenfold  its  normal 
quantity  in  the  same  time.  Activity  or  muscular  work 
on  the  other  hand  hardly  increases  the  quantity  of  urea 
excreted  by  a  man. 

The  breath  in  diseases  may  contain  carburetted  hydro- 
gen (of  which  a  trace  is  also  excreted  in  health)  and 
volatile  matters  at  present  unknown,  ammonia  being 
perhaps  amongst  them.  These  investigations  have  only 
just  become  possible  by  the  invention  of  an  apparatus 


58  CHEMICAL   PHYSIOLOGY. 

which  permits  entire  persons  to  be  observed  for  days 
in  glass  chambers,  and  their  excretions  to  be  accurately 
analysed  and  determined.  By  means  of  this  method 
it  has  now  been  found  that  man  during  sleep  stores  up 
a  quantity  of  oxygen  in  his  body,  particularly  his  mus- 
cles, which  is  therefore  ready  for  the  production  of  force 
the  moment  it  may  be  wanted.  This  explains  the 
phenomena  of  activity  and  rest  much  better  than  they 
could  hitherto  be  defined. 

The  faeces  contain  all  insoluble  residues  of  the  food, 
some  decomposed  and  altered  bile  acid,  changed  cholo- 
phasine,  myochrome,cholesterine  changed  into  excretine, 
some  peculiar  fatty  and  odoriferous  matters,  besides  a 
little  phosphate  of  magnesium  and  calcium.  They  vary 
with  the  diet,  being  dark,  semifluid,  and  of  small  bulk 
after  meat  diet,  but  of  large  bulk,  paler  and  more  solid, 
after  bread  diet.  Boiled  with  sulphuric  acid  they  yield 
a  matter  which  has  a  peculiar  spectrum. 

The  fasces  of  children  at  the  breast  contain  choles- 
terine,  and  besides  caseine  and  undefined  matter,  a  yel- 
low matter  soluble  in  alcohol,  intestino-luteine.  This 
possesses  one  absorption-band  in  its  spectrum,  at  the 
beginning  of  blue. 

The  anomalies  of  fasces  are  still  less  known  than  their 
normal  composition.  The  cholera  evacuations  were 
fully  described  in  my  report  on  cholera.  Their  spec- 
trum may  be  compared  with  stercorine  on  the  one,  and 
acid  cruentine  on  the  other  hand. 

Iron  preparations  taken  into  the  stomach  colour  the 
fasces  black,  mercurial  ones  green.  This  latter  fact 
gave  rise  to  a  fallacy  now  exploded,  namely,  that  mer- 


mucous  eva- 


CHEMICAL    PHYSIOLOGY.  59 

cury  was  a  cholagogue  and  increased  the  excretion  of 
bile.  Bile  (not  decomposed)  has  never  yet  been  found 
in  any  faeces.  Most  remarkable  and  suggestive  is  the  An0xan  in 

n  . 

discovery  by  Liebig  of  alloxan  in  the  mucous  evacua- 
tions  from  a  case  of  intestinal  catarrh.  Alloxan  is  a 
product  of  decomposition  by  oxydants  of  uric  acid,  and 
precedes  the  formation  of  urea.  Possibly,  therefore, 
functions  of  chemolysis  are  allotted  to  the  intestine 
which  at  present  we  place  into  other  organs,  or  know 
not  where  to  localise.  Gout  might  find  an  explanation 
in  the  failure  of  this  chemolytic  action,  for  uric  acid 
once  in  the  blood  seems  as  far  out  of  the  reach  of  oxygen 
as  sugar  in  the  blood  is  in  diabetes.  Imperfect  diges- 
tion  further  causes  the  production  of  gases,  of  which 
carbonic  acid  constitutes  the  main  bulk,  but  is  mixed 
with  combustible  marsh-gas,  CH4,  and  some  hydrothion 
H2S.  This  development  in  diseases  rises  to  painful 
height,  and  in  typhus,  e.g.,  produces  sometimes  an 
almost  suffocating  tympanites  or  meteorismus. 


ANALYTICAL    GUIDE. 


Acetic  acid,  C2H402. — 1.  Extraction  from  animal  sub- 
stances. Extract  the  substance  with  boiling  water ; 
neutralise  by  soda  if  acid,  and  if  dilute,  evaporate  to  a 
reasonable  bulk.  Distil  with  dilute  sulphuric  or  phos- 
phoric acid;  neutralise  the  distillate  with  soda,  and 
evaporate  to  the  consistence  of  an  extract.  Treat 
this  like  the  extract  of  urine,  now  to  be  described. 

2.  Extraction  from  urine.  Evaporate  fresh  urine  to 
an  extract,  and  decant  from  crystals  of  sodium  chloride 
and  other  deposited  matters.  Mix  with  a  sufficient 
quantity  of  sulphuric  acid  to  decompose  nearly  all  the 
urea,  and  distil  the  mixture  from  a  retort.  Neutralise 
the  distillate  with  sodium  carbonate,  and  evaporate  to 
a  low  bulk.  Add  excess  of  somewhat  dilute  sulphuric 
acid;  allow  benzoic  acid  to  crystallise  and  filter. 
Neutralise  the  filtrate  again  with  soda  and  evaporate  to 
a  low  bulk ;  and  if  you  desire  to  prove  the  presence  of 
and  extract  formic  acid,  proceed  as  stated  under  that 
head.  Then  evaporate  the  soda  salt  to  dryness,  and 
heat  in  a  retort  with  excess  of  concentrated  sulphuric 
acid.  The  f ormiate  will  be  destroyed,  yielding  carbonic 


62  ACETIC   ACID. 

oxyde  and  carbonic  anhydride,  while  the  acetic  acid  will 
distil  over  unchanged  and  highly  concentrated,  at  a 
temperature  not  exceeding  120°  C. 

3.  Place  this  concentrated  distillate  in  a  tube  in  a 
mixture  of  ice  and  water.     It  will  begin  to  form  white 
crystals  below  16°  C.,  and  ultimately  solidify  in  a  white 
crystalline  mass. 

4.  Allow  to  thaw,  and   pour   off   the   portion  first 
liquefied,  which  is  somewhat  watery. 

5.  Place  the  crystals  in  a  very  small  retort,  provided 
with  a  thermometer  in  its  tubule,  and  with  a  condenser 
attached  to  its  neck,  and  heat.     The  acetic  acid  will 
distil  over  completely  at  120°  C.,  giving  an  inflammable 
vapour. 

6.  Unite  the  decanted  and  distilled  acid,  and  dilute 
with  water.    Boil  with  excess  of  pure  baryum  carbonate, 
filter,  and  evaporate  to  crystallisation.     The  crystals, 
monohydrate   of   baryum   acetate,  C4H6Ba04  +  H20, 
contain  6*59  per  cent,  of  water  of  crystallisation,  to  be 
expelled  at  100°  C.,  and  50*18  per.  cent,  of  Ba,  to  be 
determined  as  sulphate,  by  heating  in  platinum  crucible 
with  sulphuric  acid. 

7.  Heat  some  dry  baryum  acetate ;  it  will  fuse,  and 
give  off  vapours  of  acetone. 

8.  Dissolve  the  baryum  acetate  in  water,  heat,  and 
decompose  exactly  with  sodium  carbonate.     Filter  from 
baryum  carbonate,  and  examine  the  solution  of  sodium 
acetate  as  follows. 

9.  Add  a  few  drops  of  ferric  chloride :  a  dark  red 
colour  will  be  produced.    Boil ;  a  brown-red  precipitate 
will  fall,  leaving  the  liquid   colourless.      To   another 


ALBUMEN.  63 

portion  of  the  red  solution  add  hydrochloric  acid.     It 
will  turn  light  yellow. 

10.  Add   silver   nitrate    solution.      If    the    sodium 
acetate  solution  is  concentrated,  a  white  precipitate  of 
silver  acetate  will  ensue.     If  both  solutions  are  dilute 
no  change  will  be  observed  even  on  boiling. 

11.  Evaporate  the  sodium  acetate  solution  to  dryness. 
Heat  a  portion  with  alcohol  and  sulphuric  acid.    Acetic 
ether  will  be  formed  and  recognised   by  its  peculiar 
and  agreeable  odour. 

Albumen,  or  white  of  egg. — 1.  Break  a  fresh  hen's 
egg,  separate  off  the  yelk  and  chalazae;  dilute  the 
white  with  three  or  four  times  its  bulk  of  water,  filter, 
and  use  the  clear  liquid  for  the  following  experiments. 

2.  Place  a  portion  in  a  test-tube,  insert  a  thermo- 
meter, and  warm  gently  in  a  water  bath  ;  at  66°  0.  the 
solution  will  become  opalescent,  and  about  80°  0.  the 
albumen  will  coagulate,  and  be  precipitated  in  white 
flakes,  which  do  not  dissolve  on  boiling. 

3.  Add   a   little   nitric   acid;  the   albumen   will  be 
precipitated  white. 

4.  Add  an  excess  of  strong  alcohol ;  the  albumen  is 
precipitated. 

5.  Add  a  solution  of  corrosive  sublimate,  and  observe 
that  an  insoluble  compound  of  the  salt  and  albumen  is 
precipitated.     Upon  this  reaction  is  based  the  use  of 
white  of  egg  as  an  antidote  in  cases  of  poisoning  by 
corrosive  sublimate. 

6.  Acidify  a  portion  of  the  albumen  solution  with 
acetic  acid,  and  observe  that  no  precipitate  is  produced. 


64  ALBUMEN. 

But  on  boiling  the  whole  of  the  albumen  is  precipi- 
tated. After  nitration  and  drying  weigh  the  precipi- 
tate. This  is  a  good  method  for  estimating  the  quantity 
of  albumen  present  in  any  colourless  liquid. 

7.  Add  a  watery  solution  of  creasote,  or  of  crystallised 
carbolic   acid,    or   of   tannic   acid,  to   an   albuminous 
solution.     The  albumen  is  precipitated. 

8.  Add  a  solution  of  salt  to  the  albumen  solution, 
and  then  phosphoric,  tartaric,  oxalic,  or  lactic  acid.     A 
precipitate  of  albumen  will  ensue. 

9.  Expose  some  undiluted  albumen  in  a  thin  layer 
on  a  white  porcelain  plate  to  the  air.     It  will  dry  into 
a  pale  yellowish,  translucent,  fissured  mass,  which  is 
slowly  but  entirely  soluble  in  water. 

10.  Chemolyse  albumen  by  the  following  process  :— 
Boil  the  white  of  several  eggs  with  excess  of  dilute 
sulphuric  acid  for  three  hours.    Then  treat  the  solution 
with  milk  of  lime  until  alkaline.     Distil   the  mixture 
from  a  tin  bottle,  and  observe  in  the  distillate  ammonia, 
a  compound  ammonia,  and  a  volatile  sulphur  compound, 
which  yields  sulphur  and    sulphuretted   hydrogen  on 
addition  of  an  acid.     Extract  with  water,  and  filter  the 
residue  in  the  bottle.     Treat  the  solution  with  a  slight 
excess  of  dilute  oxalic  acid ;  remove  the  excess  of  the 
latter  and  some  sulphuric  acid  by  a  little  lead  acetate, 
and  the  excess  of  the  latter  by  sulphuretted  hydrogen. 
Filter  warm,  and  evaporate  to  slight   crystallisation. 
All  tyrosine  with   little   leucine   will   crystallise   out. 
Further   evaporation   will   yield   more   leucine. .     The 
liquor  contains  several  other  products,  which  are  dis- 
tinguished by  a  powerful  green  fluorescence.     Examine 


ALCOHOL.  65 

this  in  the  cone  of  sunlight  produced  by  a  lens. 
Examine  tyrosine  and  leucine  as  directed  under  those 
articles. 

11.  Add  to  coagulated  albumen  some  concentrated 
hydrochloric  acid,  and  heat  or  allow  to  stand  for  some 
time.     The  albumen  will  dissolve  and  form  a  blue  or 
violet  solution,  which,  before  the  spectroscope,  shows 
an  absorption  band  in  yellow  and  green. 

12.  To  coagulated  albumen  add  concentrated  nitric 
acid ;  it  will  slowly  dissolve,  forming  a  yellow  solution. 
To  this  add  a  small  quantity  of  mercurous  nitrite  and 
boil,  when  a  crimson  precipitate  will  form. 

Alcohol,  C2H60. — 1.  In  order  to  obtain  alcohol  from 
organic  tissues,  or  fluids  which  may  contain  it,  heat, 
coagulate,  and  distil  them  or  their  cold  prepared  watery 
extracts  from  a  copper  or  tin  retort.  To  urine  add 
some  tannic  acid  before  distillation.  The  distillate 
obtained  is  to  be  made  alkaline  with  caustic  potash,  and 
again  distilled.  Observe,  if  desirable,  volatile  acids  in 
residue  in  retort.  The  distillate  is  now  acidified  with 
sulphuric  acid,  to  fix  volatile  alkali,  and  again  distilled, 
This  third  distillate  contains  all  the  alcohol,  but  no 
volatile  acids  or  alkalies. 

2.  Produce  a  test  solution  by  dissolving  one  part  of 
dichromate  of  potassium  in  three   hundred   parts   of 
sulphuric  acid. 

3.  Mix   a   portion  of  the   distillate   with   twice   its 
volume  of  concentrated  sulphuric  acid.     Pour  a  small 
quantity  of  this  mixture  into  a  quantity  of  test  solu- 
tion, and  perceive  that  where  the  one  fluid  touches  the 

5 


66  ALCOHOL. 

other  there  is  a  deep  green,  and  then  a  lighter  green, 
colour  produced.  One  fourth  to  one  tenth  of  a  grain 
of  alcohol  in  half  an  ounce  of  water  will  yet  be  indi- 
cated by  this  test.  Prove  this  by  experiments  with 
pure  alcohol. 

4.  By  the   foregoing   process   you   can   prove   the 
presence  of  alcohol  in  from  two  to  six  ounces  of  urine 
secreted  a  few  hours  after  the  drinking  of  spirituous 
liquors. 

5.  Quantitative  determination  of  small  quantities  of 
alcohol  by  transformation  into  acetic  acid.     Enclose 
the  distillate  with  a  certain  quantity  of  the  dichromate 
and  sulphuric  acid  mixture  in  a  strong  flask,  stop  it 
air-tight  with  a  caoutchouc  stopper,  and  tie  it  down 
well  by  means  of  wire.     Heat  this  flask  for  two  hours 
in  a  water-bath  to  between  80°  and  90°  C.,  never  to  the 
boiling-point;  then  attach  the   flask  to  a  condenser, 
and   distil   the   newly-formed   acetic   acid    out   of  it. 
Determine  the  acidity  of  the  distillate  by  volumetric 
analysis,  with  a  standard  solution  of  caustic  soda. 

6.  In  case  larger  quantities  of  alcohol  are  contained 
in  the  matters  to  be  examined — e.  g.  vomited  matter, 
contents  of  stomach  or  intestines,  blood,  brain,  muscles, 
or  urine  in  quantity — then  the  distillate  can  be  con- 
densed by  successive  distillations,  in  which  one  half  of 
the  liquid  is  driven  over  every  time,  and  the  liquid  in 
the   retort  is   each   time    mixed  with   common   salt. 
Ultimately  the  distillate  will  smell  of  alcohol,  and  burn 
when  exposed  to  flame.     It  can  then  be  made  anhy- 
drous by  boiling  with  and  distilling  from  quicklime  or 
anhydrous   copper   sulphate.     Its  specific   gravity  at 


ALLANTOINE.  67 

0°  0.  should  be  O8095;  at  14°  0.,  07982.  It  should 
boil  at  78°  0.  under  a  pressure  of  760  millimetres  of 
the  barometer. 

Allantoine,  C4H6N03. — 1.  Glassy,  tasteless  prisms. 
Obtain  from  the  allantoic  liquid  of  cows  by  evaporating 
to  one  fourth  of  its  bulk.  The  crystals  of  allantoine 
deposited  on  cooling  redissolve  in  hot  water,  and  boil 
with  a  little  good  animal  charcoal. 

2.  From  the  urine  of  calves.     Obtain  the  urine  by 
tying  of  bladder  during  killing  process.     Evaporate  it 
till  syrupy,  and  allow  to  stand  for  several  days ;  dilute 
with  water,  collect  the  deposit  and    wash  it  with  a 
little  water.     Boil  the  crystalline  residue  with  water 
and  animal  charcoal  and  filter  hot.    The  allantoine  will 
be  deposited  in  crystals  on  cooling. 

3.  Prepare  allantoine  from  uric  acid  as  follows  : — 
Take  20  grm.  of  uric  acid,  stir  up  in  300  to  400  c.  c.  of 
water,  add  a  small  quantity  of  acetic  acid,  gradually 
introduce  100  grm.  of  lead  peroxyde,  and  expose  to 
sunlight  for  some  time.     Boil,  filter,  and  evaporate  the 
nitrate  until  on  cooling  the  allantoine  crystallises  out. 

4.  Observe  that  it  is  slightly  more  soluble  in  alcohol 
than  in  water. 

5.  Boil  with  baryum  hydrate,  and  notice  evolution 
of  ammonia. 

6.  Corrosive  sublimate  will  produce  no  precipitate  in 
its  solution,  but  mercuric  nitrate  precipitates  it  in  the 
cold  even  from  dilute  solutions. 

Alloxan. —  C4H2N304.  —  1.    Add    to    strong    nitric 
acid,  contained  in  a  beaker  placed  in  cold  water,  an 


68  ALLOXAN. 

equal  weight  of  uric  acid  in  small  portions,  stirring  or 
shaking  the  mixture  constantly.  Allow  to  stand  and 
crystallise,  filter  through  a  funnel  plugged  with 
asbestos,  wash  the  crystals  with  water  at  0°  0.  and  dry 
between  filtering  paper. 

2.  Extract  organic  matters,  such  as  intestinal  con- 
tents or  evacuations  in  disease  with  water,  and  subject 
to  dialysis  on  parchment  paper.     Evaporate  the  dialy- 
sate  at  a  gentle  heat  and  ultimately  let  dry  sponta- 
neously.    If  alloxan  be  present  it  will  be  deposited  in 
crystalline   rings   which   assume   a   red   colour  when 
exposed  to  the  air  for  some  time. 

3.  Dissolve  alloxan   in   water   or   alcohol  and  add 
nitric  acid,  the  alloxan  will  be  reprecipitated. 

4.  Observe  its  astringent,  taste  and  acid  reaction  by 
litmus.     Rub  a  solution  of  it  on  a  part  of  the  skin,  and 
observe  that  it  produces  a  peculiar  and  disagreeable 
odour  and  stains  the  skin  pink,  crimson,  or  purple, 
after  some  time. 

5.  Boil  some  alloxan  with  dilute  nitric  acid  in  a  test- 
tube  fitted  with  a  cork  and  bent  tube,  the  latter  dipping 
into  a  little  lime  or  baryta  water.     Carbonic  anhydride 
will  be  evolved,  causing  a  milky  turbidity  in  the  lime 
or  baryta  water.     Nitrate  of  urea  remains  in  the  acid 
solution,  which  will  give  a  dense  white  precipitate  with 
solution  of  mercuric  nitrate. 

6.  Add  to  a  solution  of   alloxan  some  solution  of 
ferrous  sulphate,  and  a  drop  of  potash;  observe  the 
formation  of  a  deep  blue  solution  and  precipitate.    This 
solution  after  filtration  shows  no  specific  absorptions 
before  the  spectroscope. 


AMYLOID    SUBSTANCE.  69 

7.  To  a  solution  of  alloxan  add  some  baryta  water  and 
solution  of  baryum  nitrate,  and  observe  the  formation  of 
a  pink-red  solution.     This,  before   the  spectroscope, 
shows    a   specific   absorption    band   covering  orange, 
yellow,  green,  and  blue,  and  allowing  red  and  a  part  of 
blue  with  violet  to  pass. 

8.  Drop  into  a  concentrated  solution  of  lead  acetate 
heated  to  boiling  a  solution  of  alloxan,  and  observe  the 
formation  of  a  white  precipitate  of  mesoxalate  of  lead, 
and  the  liberation  of  acetic  acid.     From  the  nitrate 
urea  can  be  obtained  by  removal  of  the  lead  and  evapo- 
ration of  the  acetic  acid. 

Amyloid  substance. — 1.  Search  the  brain,  spinal 
marrow,  ependyma  ventriculorum,  ganglion  Gasseri,  or 
optic  nerve  in  disease,  particularly  so  called  chronic 
atrophy  or  locomotor  ataxia,  by  hardening  the  sub- 
stance to  be  examined  in  strong  alcohol,  then  making 
the  thinnest  possible  sections  with  a  razor  and  placing 
them  under  the  microscope. 

2.  Apply   tincture  of  iodine  dissolved  in  iodide  of 
potassium,  and  observe  that  no  blue  starch  granules 
appear. 

3.  Wash  away  the  iodine  solution  by  water  and  apply 
dilute  sulphuric  acid,  let  stand  for  some  time  and  apply 
some  iodine  solution.     The  amyloid,  if  present,  will 
now  appear  in  the  form  of  minute  blue  granules  closely 
resembling  the  iodised  starch  corpuscles  of  wheat. 

4.  Compare  the  reaction  of  amyloid  matter  with  that 
of  vegetable  lignine. 

Animal  quinoidine. — 1,  Treat  the   part  to    be  exa- 


70  ANIMAL    QTJINOIDINE. 

mined,  either  directly  or  after  previous  drying  in  a 
water-oven,  with  very  dilute  sulphuric  acid,  heating  the 
mixture  on  the  water-bath.  Repeat  this  extraction, 
mix  the  extracts,  filter  after  cooling,  neutralise  with 
caustic  soda  and  repeatedly  shake  up  with  ether  equal 
in  bulk  to  that  of  the  extract.  Distil  off  the  ether,  take 
up  the  residue  in  dilute  sulphuric  acid,  filter,  and 
observe  if  fluid  be  clear. 

2.  If  not  clear  repeat  neutralisation  with  soda  and 
extraction  with  ether,  and  resolution  in  dilute  sulphuric 
acid. 

3.  Treat  the  solution  for  fluorescence  by  exposing  it 
to  a  cone  of  sunlight,  or  of  the  spark  of  the  Ruhmkorff 
coil,  condensed  by   a  quartz -lens.     Observe  that  the 
colour  produced  is  bluish-green  when  the  solution  is 
concentrated,  but  blue  when  dilute. 

4.  Compare  this  fluorescence  with  that  of  a  very 
weak   solution  of  sulphate  of  quinine   in   water,  and 
observe  its  close  resemblance  to  it. 

Benzoic  acid,  07  H6  03. — 1.  Obtain  benzoic  acid  by  the 
process  described  under  Acetic  acid,  2. 

2.  Obtain  benzoic  acid  by  boiling  hippuric  acid  with 
excess   of    concentrated   hydrochloric    acid.      It   will 
crystallise   on   cooling.      Filter  and   wash   with   cold 
water.     Dry  in  the  air  without  using  heat. 

3.  Purify  the  acid  by  sublimation  from  a  porcelain 
capsule  covered  with  a  diaphragm  of  filtering  paper  and 
a  conical  hood  of  paper. 

4.  Heat  a  small  quantity  of  the  acid  in  a  glass  tube, 
and  observe  that  it  fuses,  then  is  volatilised  and  again 


BENZOIC   ACID.  71 

deposited  on  the  cool  parts  of  the  glass.  The  aro- 
matic smelling  vapour  causes  much  coughing  when 
inhaled  in  small  quantity. 

5.  Heat  a  small  portion  with  concentrated  sulphuric 
acid  and  observe  that  no  blackening  ensues. 

6.  Neutralise  its  hot  watery  solution  with  baryum 
carbonate,  and  evaporate  solution  of  baryum  benzoate 
to  crystallisation. 

7.  Add  to  the  solution  of  this  or  any  other  benzoate 
some  neutral  solution  of  ferric  chloride,  and  observe  the 
precipitation  of  a  buff-  coloured  precipitate  of  almost 
insoluble  ferric  benzoate.     For  diagnosis  of  this  preci- 
pitate from  succinate,  see  Succinic  acid,  4. 

8.  To  a  solution  of  a  benzoate  or  of  benzoic  acid  add 
some  cupric  acetate  and  warm  ;  a  blue  precipitate  of 
rather  insoluble  basic  benzoate  of  copper  will  be  formed. 


.  —  Qualitative  and  systematic  analysis.  1.  Col- 
lect the  bile  from  the  gall-bladders  of  dead  persons  or 
animals,  or  from  biliary  fistulas  of  the  latter  produced 
by  art.  Observe  its  colour,  formed  or  crystalline 
ingredients  if  any,  and  its  reaction,  which  should  in 
health  be  neutral  or  feebly  alkaline. 

2.  Add  to  a  filtered  portion  a  little  acid,  and,  if  ne- 
cessary, filter  again.    Then  heat  gently  to  boiling,  and  if 
any  precipitate  ensues  albumen  is  present. 

3.  Mix  the  bile  with  five  or  six  volumes  of  absolute 
alcohol,   and  let   stand;    filter   from   the  precipitated 
mucus    and  cholesterine  (and  albumen   if    such    was 
abnormally  present).      Evaporate  the  solution  to  dry- 
ness,  and  use  the  residue  as  purified  bile. 


72  BILE. 

4.  Purified  bile  dissolved  in   absolute   alcohol,  and 
mixed  with  an  equal  bulk  of  ether,  forms  an  immediate 
deposit.     Place  this  mixture  in  freezing  air,  or  into 
a  freezing  mixture,  and  after  twenty-four  hours  observe 
that  crystals  are  formed  and  the  liquid  is  clear.    These 
crystals  are  a  mixture  of  glykocholate  and  tauro-cholate 
of  sodium.     Evaporate  the  ether  and  observe  the  crys- 
tals of  cholesterine  and  fats. 

5.  Add  to  a  watery  solution  of  purified  bile  neutral 
lead  acetate  as  long  as  a  precipitate  is  produced.     The 
white  plaster -like  deposit  is  glykocholate  of  lead. 

6.  Add   to   the  filtrate,   from  the   glykocholate,   a 
solution  of  basic  lead  acetate  as  long  as  a  precipitate  is 
produced.     The  latter  consists  of  taurocholate  of  lead. 

7.  Filter  the  liquid  and  treat  with  hydrothion ;  filter 
again,  evaporate  to  dryness  and  burn  the  residue  to  a 
white  ash.      Observe  that  it   consists  principally   of 
sodium    carbonate,   little   potassium   carbonate,   some 
chlorides,  and  earthy  salts  in  small  quantity. 

8.  Boil  a  quantity  of  purified  bile  dissolved  in  water 
with  excess  of  caustic  baryta  for  several  hours.     Sepa- 
rate solution  from  insoluble  salt  and  crystals  which 
form  on  cooling,  and  remove  excess  of  baryta  by  car- 
bonic acid.     Add  to  the  concentrated  solution  platinic 
chloride,  and  observe  and  examine  crystalline  precipi- 
tate of  choline -platinum  chloride. 

9.  Remove  from  this  solution  the  excess  of  platinum 
by  hydrothion,  evaporate  to  small  bulk  and  add  much 
absolute  alcohol.     Let  stand  for  twenty-four  hours,  then 
isolate  crystals,  recrystallise  from  hot  water,  and  study 
the  pure  taurine. 


BILE.  73 

10.  From  the  alcoholic  solution  from  which  taurine 
has  been  deposited,  evaporate  off  the  alcohol  and  dis- 
solve residue  in  a  little  water.     Remove  hydrochloric 
acid  by  a  little  silver  oxyde,  the  latter  by  hydrothion, 
and  crystallise  nitrate.     Separate  the  crystals  of  glyko- 
koll  from  the  crystals  of  inorganic  salts  and  examine 
them. 

11.  Add  to  crude  or  purified  bile  dissolved  in  water, 
a  little  acetic  or  hydrochloric  acid,  and  extract   the 
mixture  with  chloroform.      Distil  off  the  chloroform 
and  extract  the  residue  with  boiling  alcohol.     Fatty 
acids  and  cholesterine  will  dissolve,  and  bilirubine  will 
remain  undis solved,  as  a  red  powder. 

12.  Add  to    crude   bile  a   very  small  quantity  of 
acetic  or  hydrochloric  acid,  and   shake    with  animal 
charcoal  until  colourless.      "Wash   the    charcoal  with 
water    until    the    water   comes    away    pure.      Then 
extract  the  charcoal  with  much  boiling  alcohol.     Bili- 
fuscine   will   go    into     solution    and   form   a    brown 
liquid. 

13.  Evaporate  a  weighed  quantity  of  bile  to  dryness 
and  determine  dry  residue.     It  will  be  found  to  exceed 
five  per  cent.,  and  approach  ten  per  cent,  of  the  weight 
of  the  bile. 

14.  Burn  a  weighed  quantity  of  dry  bile  with  nitre 
in  a  platinum  dish,  and  in  the  residue  determine  sul- 
phuric acid  by  baryta  in  the  usual  manner.     From  the 
quantity  of  sulphur  found  calculate  the  quantity  of 
taurocholic  acid  present  in  the  original  bile.     One  part 
of  sulphur  indicates  16*28  parts  of  taurocholic  acid.. 

15.  To  some  bile  diluted  with  water  and  spread  on  a 


BILE. 


white  porcelain  dish  add  a  few  drops  of  red  nitric 
acid.  A  precipitate  will  ensue  around  every  drop,  and 
then  a  red,  blue,  green,  and  yellow  coloration  will  pro- 
ceed in  rings  from  each  drop  as  a  centre,  due  to  the 
reaction  of  the  colouring  matters  with  nitrous  and 
nitric  acid. 

16.  To  a  few  drops  of  bile  placed  in  a  porcelain  dish 
add  a  drop  of  a  solution  of  cane-sugar,  and  then  con- 
centrated sulphuric  acid  drop  by  drop  with  agitation. 
After  a  little  time  the  mixture  will  assume  a  purple-red 
colour,  and  show  the  following  spectrum : 


A  a  BO 


Spectrum  of  Pettenkofer's  test. 

The  colour  of  the  solution  will  be  destroyed  by 
water  and  alcohol. 

17.  In  diseased  conditions  of  the  bile,  in  fatal  cases 
of  cholera,  the  liquid  contained   in   the  gall-bladder 
contains  no  bile-acids. 

Observe  that  in  such  cases  the  purple  reaction  just 
described  cannot  be  obtained  even  with  the  concen- 
trated alcoholic  extract. 

18.  Boil  purified  bile  dissolved  in  water  with  excess 
of  hydrochloric  acid  in  a  flask  for  several  hours,  until 
a  clear  reddish  fluid  is  obtained  and  a  dark  pitchy 
resin  is  deposited.     The  resin  is  choloidic  acid  and 


BILE.  .  75 

dyslysine,  which  contains,  however,  some  undecom- 
posed  glykocholic  and  taurocholic  acid.  Decant  and 
filter  the  acid  liquid,  and  evaporate  to  dryness  repeat- 
edly to  expel  all  free  acid.  Then  shake  up  residue  in 
spirit  and  let  stand.  Taurine  will  deposit  in  crystals ; 
hydrochlorate  of  glykokoll  and  chloride  of  sodium  will 
remain  in  solution.  Separate  the  latter  by  crystalli- 
sation or  by  the  process  described  under  10. 

19.  Filter  fresh  bile  through  a  cloth,  or  let  stand  for 
twenty-four  hours,  and  decant  the  clear  portion.  Place 
in  a  stoppered  bottle  in  a  cool  place  or  cellar  for 
several  weeks  or  months.  After  that  time  filter  red 
liquid  from  deposit.  The  liquid  contains  a  new  acid, 
which  gives  precipitates  with  the  chlorides  of  calcium 
and  baryum,  such  as  are  not  obtainable  from  fresh  bile. 
The  deposit  after  washing  and  pressing  should  be 
treated  with  boiling  alcohol.  Cholic  acid  will  dissolve 
and  will  deposit  in  crystals  on  cooling.  Bilirubine, 
and  phosphates  of  lime,  and  magnesia  with  ammonia 
in  crystals,  coloured  greenish  by  impurity,  will  remain. 
Extract  the  bilirubine  by  chloroform,  and  purify  the 
earthy  salts  by  calcination,  or  analyse  them  by  the 
ordinary  processes. 

Bilifuscme  (probably  C9HnN03). —  1.  Powder  a 
brown  human  gallstone  and  extract  cholesterine  with 
boiling  ether.  Treat  the  powder  with  water  and  a 
little  hydrochloric  acid,  and  wash  it  to  neutrality. 
Then  extract  again  with  boiling  ether  to  remove  fatty 
acids,  and  boil  the  powder  with  absolute  alcohol. 
Bilifu seine  will  form  a  brown  solution  and  remain  after 


76  BILIFUSCINE. 

evaporation  of  tlie  alcohol  as  a  black,  shiny,  brittle 
mass,  or  as  a  dark  brown  powder. 

2.  Dissolve  a  small  quantity  in  dilute  potash  lye,  and 
reprecipitate  by  hydrochloric  acid  brown  flakes. 

3.  Dissolve  in  dilute  ammonia,  and  add  chloride  of 
calcium  or  baryum,  when  bilifuscate  of    calcium   or 
baryum  will  fall  down  in  brown  flakes. 

4.  Observe  that  bilifuscine  is  not  soluble  in  chloro- 
form, and  when  exposed  to  the  air  in  alkaline  solution 
does  not  yield  biliverdine. 

5.  Spread  an  alkaline  solution  on  a  white  dish,  and 
add  a  drop  of    red    nitric    acid.      Red,   blue,  green, 
violet,  and  yellow  coloured  rings  will  be  successively 
produced. 

Bilirubine,  synonym  Cholophceine,  C9H9N02. — 1.  Ex- 
tract some  powdered  oxgallstone  successively  with 
water,  alcohol,  dilute  hydrochloric  acid,  boiling  alcohol, 
and  ether ;  then  boil  the  dry  powder  with  dry  chloro- 
form, and  exhaust  with  this  agent.  Distil  the  chloro- 
form from  the  red  solutions,  but  not  quite  to  dryness. 
To  the  residue  add  several  volumes  of  absolute  alcohol 
and  let  stand  twenty-four  hours.  There  will  be  depo- 
posited  a  brilliant  red  powder  mixed  with  steel-blue  or 
brown  crystals.  Both  the  powder  and  the  crystals  are 
pure  bilirubine,  and  can  be  separated  by  levigation  with 
much  absolute  alcohol.  After  washing  with  alcohol 
and  ether,  until  the  washings  are  purely  yellow  and 
not  green,  the  product  is  pure.  Dry  under  the  air- 
pump. 

2.  Human  gallstones,  by  the  foregoing  treatment. 


BlLIRUBINE.  77 

will,  after  extraction  of  the  bilifuscine,  also  yield  bili- 
rubine, but  in  very  small  quantity  only. 

3.  Human  bile  or  ox  bile  will  by  putrefaction  deposit 
bilirubine.     See  Bile,  19. 

4.  Saturate  some  very  dilute  aqueous  solution  of 
ammonia  witli  bilirubine  in  excess,  and  filter  quickly. 
In  this  solution  nitrate  of  silver  produces  a  precipitate 
of    neutral    monohydrated    cholophgeinate    of    silver 
C9H10AgN03.      In   the    same    solution    chlorides    of 
baryum  and  calcium  produce  red  precipitates  of  the 
half-acid  salts,    sesqui-cholophseinates,  which  contain 
three  atoms  of  cholophseine,  two  atoms  of  water,  and 
one  (didynamic)  atom  of  metal,  yielding  the  formula 
C27H29M''N308. 

5.  Dissolve   some   cholophseine   in   excess   of   am- 
monia.    To  this  solution  add  chloride  of  calcium  or 
baryum,  and  observe  the  formation  of  dark  red  precipi- 
tates of  the  neutral  salts  of  the  formula  C18H20MISr206. 

6.  Dissolve  some  bilirubine  in  caustic  or  carbonated 
alkali,  and  expose  to  the  air  for  some  days,  frequently 
shaking  the  solution  with  air.     Observe  that  the  red 
solution  becomes  purely  green.     Then  precipitate  by 
hydrochloric  acid,  wash  the  green  flakes  by  decanta- 
tion,  and  dissolve  in  absolute  alcohol.     The  latter  on 
evaporation  will  leave  pure  biliverdine  C8H9N02. 

7.  Add  to  an  ammoniacal  solution  of  cholophseine 
concentrated  nitric   acid  drop  by  drop  until  a   blue 
precipitate  is   formed.      Isolate  quickly  by  filtration, 
and  after  washing  dissolve  in  alcohol.     This  blue  solu* 
tion  of  cholocyanin  has  the  following  spectrum : 


78 

A  a  B  G         D 


BILIRUBINE. 
Eb        F  G 


HH' 


AaBC        D 


Spectrum  of  Cholocyanine. 
Eb         F  G 


HH' 


Spectrum  of  Cholocyanine  dissolved  in  water. 

• 

8.  Treat  some  dry  cholophaeine  with  fuming  or 
much  concentrated  sulphuric  acid,  and  triturate  in  a 
mortar ;  let  the  green  solution  attract  water  from  the 
air,  and  then  add  more  water.  Several  green  products 
insoluble  in  water  will  be  formed.  One  of  these,  in- 
soluble in  alcohol,  is  cJiolothalline,  C9HnN03.  Another, 
soluble  in  alcohol,  has  the  following  spectrum  : 


AaBC         D 


Eb 


HIT 


Spectrum  of  soluble  Cholotlialline. 

9.  Expose  some  dry  bilirubine  to  the  vapours  of 
bromine,  and  observe  that  it  immediately  becomes 
violet-brown.  Exposed  to  the  air  this  will  deliquesce 
and  form  a  blue  solution  of  hydriodate  of  dibromo- 


BiLIEUBINE.  79 

bilirubine.  Dried  at  100°  the  acid  will  be  expelled,  and 
pure  dibromo -bilirubine,  C9H7Br2N03,  will  remain  as  a 
black-blue  powder.  It  dissolves  in  water  with  the  aid 
of  any  acid,  and  forms  a  splendid  blue  solution.  It 
also  dissolves  in  alcohol  and  a  little  in  ether,  but  these 
solutions  are  discoloured  after  some  time.  It  dissolves 
in  caustic  alkali  with  a  red  colour,  and  acids  produce  a 
red  precipitate.  These  tests  under  9  can  be  performed 
with  a  quantity  of  less  than  a  grain. 

Blood. — 1.  Take  a  quantity  of  blood  directly  from  a 
blood-vessel  of  an  animal  or  of  man,  and  stir  it  briskly 
with  a  rod  for  ten  minutes.  Filter  through  a  cloth 
and  wash  the  fibrine  with  water  until  colourless. 

2.  If  it  is  desired  to  determine  the  quantity  of  the 
fibrine  weigh  the  collected  blood  in  a  stoppered  bottle 
containing   a   chain    of    glass   beads,    shake   for   ten 
minutes,  add  water,  let  stand  and  deposit,  decant  the 
fluid,  wash  with  water  by  decantation,  ultimately  with 
water  containing  a  little  chloride  of  sodium,  collect, 
dry,  and  weigh  the  fibrine. 

3.  Mix  one  volume  of  saturated  chloride  of  sodium 
solution  with  from  nine  to  ten  volumes  of  distilled 
water.      To  this   solution  add   one  volume  of  blood, 
beaten  and  filtered  through  calico,  and  stir.     Let  the 
mixture  stand  at  a  very  low  temperature  in  ice  and 
water.     When  the  corpuscles  are  deposited  decant  the 
supernatant  liquid,  and  stir  the  deposit  again  with  the 
same  quantity  of  salt  water  as  at  first*     Repeat  this 
washing  operation  a  third  and  fourth  time,  when  the 
blood-corpuscles  will  be  free  from  serum. 


80  BLOOD. 

4.  Shake  the  blood-corpuscles  thus  freed  from  serum 
with  ether  and  water,  and  observe  that  the  red  hema- 
tocrystalline  dissolves  in  the  water.  Filter  this  solution 
without  delay,  and  expose  to  a  low  temperature.  If 
the  blood  came  from  dogs,  rats,  guinea  pigs,  or  squir- 
rels, it  will  crystallise  at  once,  but  if  it  came  from 
birds  will  crystallise  only  after  the  addition  of  one 
quarter  of  the  volume  of  the  solution  of  alcohol  of  80% 
strength,  and  exposure  to  a  cold  of  from — 5°  to  — 10°  0. 
Separate  the  crystals  by  nitration,  wash  with  alcohol 
of  20%  strength  by  volume,  press  them  between  fil- 
tering paper,  redissolve  in  a  minimum  of  water,  filter 
again,  mix  with  one  quarter  volume  of  alcohol  of  80%, 
and  expose  again  to  the  low  temperature.  The  crys- 
tals of  hematocrystalline  will  re-form  in  a  purer  state 
than  before.  If  the  blood  employed  in  this  process  be 
human  or  veterinary,  no  crystals,  but  only  an  amor- 
phous deposit  of  hematocrystalline,  will  be  obtained. 

5.  Burn  a  quantity  of  these  crystals  in  a  platinum 
crucible  and  observe  that   they  leave   a  quantity   of 
red  iron  oxyde  corresponding   to    0*43%    of   metallic 
iron  in  the  crystals.     Determine  the  other  elements 
and  observe    that   all  analyses    lead  to  the  formula 
ccoo  HOGO  Ni5i  Fe  Ss  0177,   giving   an  atomic  weight  of 
13280. 

6.  Place  a  concentrated  solution  of  hematocrystalline 
in  a  test-tube  before  the  slit  of  the  spectroscope,  and 
observe  that  it  excludes  all  light  but  the  red.     Then 
dilute  the  solution  with  water,  and  observe  that  green 
and    blue    light    passes,    while    in    yellow    and    the 
beginning  of  green  a  dark  space  remains.     On  further 


BLOOD. 


81 


dilution  tile  latter  is  seen  to  consist  of  two  absorption 
bands,  one,  situated  towards  the  red,  close  upon  the 
D  line,  is  narrower,  darker,  and  better  defined,  while 


AaBC        D 


HH' 


Spectrum  of  Blood. 

the  second  one  situated  towards  the  green  on  the 
side  of  the  E  line,  which  is  towards  D,  is  wider  and 
paler.  Dilute  the  solution  gradually  and  observe  how 
the  bands  become  paler.  Study  these  phenomena 
upon  all  kinds  of  red  blood  and  red  muscular  tissue. 

7.  Treat  a  solution  of  blood  which  exhibits  the  two 
absorption  bands  with  hydrogen  or  arseniuretted 
hydrogen  gas,  or  with  a  solution  of  ferrous  sulphate 
containing  tartaric  acid  and  excess  of  ammonia,  the 
air  being  in  each  case  excluded  from  contact  with  the 
mixture,  and  observe  that  the  colour  of  the  solution 
alters  to  purple^  and  that  before  the  spectroscope  only 
one  broad  band  is  seen  in  the  place  of  the  former  two. 


AaBC        D 


Eb 


HH' 


Spectrum  of  reduced  Hematocrystalline. 

8.  Shake  up  the  solution  prepared  according  to  the 

6 


82  BLOOD. 

previous  paragraph  with  air,  and  observe  that  the  one 
band  disappears  and  the  two  bands  reappear.  The 
one  band  is  peculiar  to  reduced  or  venous,  the  two 
bands  are  characteristic  of  oxydised  or  arterial  hemato- 
crystalline. 

9.  Treat  some  diluted  hematocrystalline  solution  or 
blood  with  carbonic  oxyde,  and  notice  that  the  colour 
becomes  more  bluish  than  either  arterial  or  venous 
blood,  and  that  the  spectrum  is  that  of  arterial  blood, 
but  that  the  bands  are  moved  a  little  more  towards 
the   violet  end.      This  combination   of  carbonic  oxyde 
with    hematocrystalline    cannot   be   dissolved    by    any 
rediicing  agent,  and  is  the  cause  .of  death  in  cases  of 
poisoning  by  charcoal  vapours. 

10.  Treat  some  diluted  blood  with  nitrous  oxyde  gas 
and  observe  that  the  absorption  bands  become  a  little 
paler.     This  is  due  to  the  expulsion  of  oxygen  from 
and  the  combination  of  nitrous  oxyde  with  the  hemato- 
crystalline. 

11.  Treat  a  solution  of  blood  with  hydrothion  or 
ammonium   sulphide,  and  observe  that  the   spectrum 
becomes    changed,   three   bands    as  in  the  following 
engraving  making  their  appearance. 


AaBC        D  Eb        F  G  HH 


Spectrum  of  Blood  treated  with  hydrothion. 

12*  Treat   some    hematocrystalline   with   acetic  or 


BLOOD.  83 

sulphuric  acid  and  alcohol,  and  observe  the  formation 
of  a  solution  of  hematine.     (See  Hematine.) 

13.  Boil  blood-corpuscles  isolated  by  the  salt-water 
process  under  3  with  alcohol,  and  extract  cholesterine 
and  lecithins.     From  the  insoluble  residue,  decomposed 
hematocrystalline,  extract  hematine  by  acid  and  alcohol, 
and  study  albuminous    residue  like  coagulated  albu- 
men. 

14.  Evaporate  the  filtered  ether  solution  obtained 
under  4,  and  observe  cholesterine  and  lecithine  in  the 
residue.     Identify  cholesterine  by  its  crystalline  form, 
and  lecithine  by  its  leaving  on  combustion  free  phos- 
plioric  acid. 

15.  Treat    blood-corpuscles   isolated    by    the    salt- 
water  process  under  3   with   water  without  stirring 
much.      The    hematocrystalline   will   dissolve   and    a 
gelatinous   matter,    the  fibrino -plastic  substance,    will 
remain  undissolved.     Add  some  ether  and  alcohol  to 
curdle  the  matter  more  completely,  filter  and  wash, 
The  matter  is  soluble  in  solution  of  sodium  chloride 
and  in  water  containing  one  tenth  per  cent*  of  hydro- 
chloric acid. 

16.  Collect  a  quantity  of  blood  and,  without  stirring 
it,  let  stand  in  a  quiet  cool  place  for  twenty- four  hours. 
Remove  the  clear  serum  with  a  pipette  or  syphon,  and 
study  as  follows  : 

17.  Shake  a  portion  with  ether,  and  observe  fats  or 
fatty  acids  in  the  residue  of  the  ether  solution. 

18*  Mix  a  measured  or  weighed  portion  of  serum  with 
several  times  its  bulk  of  water,  acidify  with  acetic  acid, 
and  boil.  The  albumen  of  serum  will  be  precipitated, 


84  BLOOD. 

Determine  its  quantity  by  washing,  extracting  with 
boiling  alcohol,  and  weighing  the  dried  precipitate. 
It  will  probably  amount  to  between  7§9  and  9 '8  % 
of  the  serum. 

19.  Evaporate   the  filtrate  from  the  albumen  pre- 
cipitate to  a  low  bulk,  and  test  for  tyrosine,  leucine, 
kreatinine,  urea,  glukose,  and  extractive  acids. 

20.  Burn  the  residue  and  examine  the  white  ash, 
which   should   amount  to    about    0'7    to    0*8    %   of 
the  serum.      Study    the   prevalence   of   sodium  over 
potassium    salts ;     of    chlorides    over    sulphates ;     of 
alkalies  over  earths ;  prove  the  presence  of  phosphoric 
acid. 

2.1.  Dry  a  weighed  quantity  of  serum,  and  determine 
total  quantity  of  dry  residue. 

22.  Dilute  clear  serum  with  ten  volumes  of  water, 
and  pass  a  current  of  carbonic  anhydride  through  the 
solution.      Let   stand   and    allow    the  fibrino ^plastic 
substance  (also  termed  paraglobuline)  to  deposit. 

23.  Dilute  the  solution,  from  which  fibrino -plastic 
matter    has  been  deposited,  by  an    addition    of  ten 
volumes  of  water,  and  neutralise  most  cautiously  with 
very  dilute  acetic    acid.      A    milky   turbidity   and   a 
subsequent  adhesive  deposit  are  formed  and  constitute 
fibrinogenous  matter. 

24.  Add  to  hydrocele  fluid,  or  to  the  fluid  of  peri- 
cardial,    pleural    or    peritoneal    exudations,    a    small 
quantity  of  fibrino -plastic  substance,  and  observe  that 
they  immediately  deposit  fibrine. 

25.  Shake  some  defibrinated  blood  in  a'  stoppered 
bottle  with  much  air  or  oxygen,  and  observe  that  it 


BEAIN.  85 

assumes  a  bright  red  colour,  and  evolves  carbonic 
anhydride.  Identify  the  latter  by  passing  it  through 
solution  of  baryta  or  lime. 

26.  Shake  some  oxydised  red  blood  with  carbonic 
oxyde,  and  observe   that    the  latter  gas  is   absorbed 
while  oxygen  is  expelled.     Shake  some  oxydised  blood 
with  carbonic  acid,  and  observe  that  some  oxygen  is 
expelled  and  carbonic  acid  absorbed,  while  the  blood 
assumes  a  dark  red-purple  colour. 

27.  Expose    blood   enclosed   in  a  piece  of  sheep's 
gut  to  chlorine  gas,  and  observe  that  the  red  colour  of 
blood  passes  into  green. 

28.  Expose    blood   so    enclosed    to    a  mixture  of 
ammonia  and  sulphide  of  ammonium  gas,  and  observe 
its  decomposition  and  dark  discoloration. 


Brain. — 1.  Free  the  brain-tissue  from  blood  by 
injecting  water  into  the  blood-vessels  while  in  the 
cranium,  or  after  removal,  and  separate  the  mem- 
branes. Ascertain  the  specific  gravity  of  the  white 
matter  to  be  about  1041,  that  of  the  gray  matter 
about  1034. 

2.  Dry  gray  matter  in  a  water  bath  and  ascertain 
loss  of  water  to   be  from  75  to  88   %,  and  the  re- 
maining solids   to  amount  to    25  to  14  % ;    whereas 
white    matter    will   lose    less   than    75    %    of  water, 
generally  about  71  per  cent.,  and  leave  25  to  29  %  of 
solids. 

3.  Extract  cerebric  acid  with  hot  ether,  as  directed 
under  Cerebric  acid, 


86  BRAIN. 

4.  Extract    cerebrine    and   protagon    with   boiling 
alcohol,  as  directed  under  those  bodies. 

5.  From  the  cold  ether  extract  containing   chole- 
sterine  and  lecithine  which  is  obtained  in  the  preparation 
of  cerebric  acid,  lecithine  is  isolated  by  the  process 
given  under  that  substance,  any  great  excess  of  the 
platinic    or  cadmium  chloride    being   avoided.       The 
filtrate  from   the  precipitated  lecithine  compound   is 
boiled  with  excess   of  plumbic  hydrate  and  filtered. 
On  cooling  a  copious  crystalline  deposit  will  form,  from 
which  pure  cholesterine  may  be  obtained  by  recrystalli- 
sation  from  boiling  alcohol, 

6.  Eub  brain-matter  in  a  mortar  with  water  con- 
taining enough  sodium  chloride  to  prevent  cerebrine 
and  cerebric  acid  from  forming  an  emulsion ;    filter 
the  mixture.     The  clear  filtrate  will  contain  potassium- 
albumen    or   casein,    which    may  be   precipitated    by 
sulphuric    acid    not    in    excess.      From    the    filtrate 
addition  of  a  few  drops  of  acetic  acid  and  boiling  will 
throw  down  albumen  if  present. 

7.  Rub  in  a  mortar  to  a  thin  milk  with  excess  of 
baryta  water,  heat  till  just  coagulated,  filter,  remove 
the  main  bulk  of  the  baryta  from  the  filtrate  by  a 
current  of  carbonic  acid,  and  the  last  traces  by  exact 
precipitation  with  sulphuric  acid  and  evaporate  to  a 
low  bulk.     Divide  this  extract  into  two  portions. 

8.  One    portion   of  the  extract    distil   with  dilute 
sulphuric  acid  to  obtain  the  volatile  acids,  acetic  and 
formic.       Examine    them    as    directed    under    those 
bodies. 

9.  The  other  portion  of  the  extract  heat  with  eth 


. 


BRAIN.  87 

slightly  acidified  with  sulphuric  acid.  Mix  the  ethereal 
solution  with  water,  distil  off  the  ether,  remove  any 
sulphuric  acid  by  cautious  addition  of  baryta  water, 
evaporate  the  filtrate  and  test  for  lactic  acid  (q.  v)  by 
the  zinc  salt,  and  for  urea. 

10.  The  part  insoluble  in  ether  must  be  diluted  with 
water,  freed  from  sulphuric  acid   by  addition  of  just 
sufficient  baryta  water,  the  nitrate  evaporated  to  a  low 
bulk   and   exhausted   with    boiling    absolute   alcohol. 
Leucine,  kreatine,  and  urea  will  dissolve,  and  some  leu- 
cine  may  crystallise  out  on  cooling.     From  the  alcoholic 
solution  expel  the  alcohol  by  distillation  till  the  aqueous 
residue  forms  not  too  thick  a   syrup,  adding  a  little 
water,    if    necessary,    and    set    aside    to    crystallise. 
Kreatine   and   leucine   will    separate    while   urea    will 
remain  in  the  mother  liquor,  and  may  be  isolated  by 
nitric  or  oxalic  acid.     (See  Urea). 

11.  The  kreatine   and   leucine   may   sometimes   be 
mechanically  separated  (the  former  being  in  crystals, 
the   latter   in   opaque   granules)    and    afterwards    be 
purified    by    crystallisation    from    alcohol.      If    not, 
dissolve  the  mixed  deposit  in  hot  water,  and  boil  with 
zinc  chloride.     On  cooling  and   standing,    kreatinine, 
zinc  chloride,  and   kreatine  will  separate  in  granules 
(see  those  bodies) .     From  the  liquid  after  precipitation 
of  the  zinc  with  ammonium  carbonate  and  boiling,  and 
evaporation  of  the  filtrate,  leucine  (and  homologues) 
may  be  isolated  by  the  process  given  under  leucine 
(q.v.). 

12.  The  portion  insoluble  in  boiling  alcohol   must 
be  exhausted  with  boiling  water.     Some  uric  acid  may 


88  BRAIN . 

remain  undissolved.  To  the  boiling  solution  add 
neutral  acetate  as  long  as  any  precipitate  is  produced. 
Filter. 

13.  The  precipitate  may  contain  lead  urate  as  well 
as  lead,  salts  of  inosic  and  similar  acids.     Suspend  in 
a    moderate  quantity  of    water    and    decompose    by 
sulphuretted  hydrogen.     The  lead  sulphide  will  retain 
most  of  the   uric  acid,  which  may  be  extracted   by 
boiling  with  water,  while  the  filtrate  will  contain  the 
inosic  acid  and  allied  bodies,  if  present. 

14.  The  filtrate  from  the  precipitate  by  neutral  lead 
acetate  must    be   precipitated  by  basic   lead   acetate 
and  cupric  acetate.     The  solution  filtered  from  these 
precipitates  may  contain  tyrosine,  which  must  be  iden- 
tified by  evaporating,  dissolving  the  crystals  or  deposit 
in  a  little  hydrochloric  acid,  precipitating  by  sodium 
acetate,  and  applying  the  mercury  nitrate  and  nitrite 
test.     (See  Tyrosine). 

15.  The   precipitate   may  contain   xanthine,  hypo- 
xanthine,   and  inosite.     Suspend  the  precipitate  in  a 
rather  large  quantity  of  water,  decompose  by  hydro- 
thion,  filter,    extract  the   lead   sulphide  with   boiling 
water  and  evaporate  the  filtrate  and  extract  together 
to  dryness.     From  the  residue  extract  the  inosite  by 
cold   water,    and   purify  by  crystallisation.     The   re- 
maining xanthine  and  ImjpoxantJiine  may  be  separated 
and  purified  by  the  processes  described  under  those 
bodies. 

16.  Burn  a  portion  of  dried  mixed  brain-matter  care- 
fully in  a  platinum  dish  (best  in  a  muffle)  and  analyse 
the  ash,  noticing  that  there  is  always  a  quantity  of 


BRAIN.  89 

free  phosphoric  acid  present  in  it.  Observe  that  it 
contains  1*74%  of  ash,  of  nearly  the  following  com- 
position : 

Acid  potassium  phosphate  55'24 

„     sodium                „          22'93 

„    iron                     „          1-23 

„     calcium               „          1-62 

„     magnesium         „          3'40 

Free  phosphoric  acid 9-15 

Sodium  chloride 4*74 

Potassium  sulphate    1'64 

Silica...  0-42 


100-37 

17.  Burn   another  portion  very   gradually,    adding 
hot  saturated  baryta  water  to  the  charring  and  charred 
matters  from  time  to  time,  in  order  to  neutralise  the 
free   phosphoric   acid   formed   by  the  destruction   of 
lecithine,  and  preserve  the  whole  of  the  chlorides  and 
sulphates  intact.     Prove  by  comparison  that  the  acid 
phosphates  found  by  process  16  are  mainly  formed  by 
the   phosphoric    acid    from    the    lecithine,    expelling 
chlorine  and  sulphuric  acid  from  the  glowing  ash. 

18.  Burn  some  dry  white  brain-matter,  and  notice 
that  it  leaves  about  1*72%  of  ash  containing  free  phos- 
phoric acid  and  a  large  amount  of  acid  phosphates. 

19.  Burn  some  dry  gray  brain-matter,  and  notice 
that  the  quantity  of  its  ash  is  only  1*16  %,  that  it  is 
alkaline,  and   contains   a   much    smaller   quantity   of 
phosphates  than  the  ash  from  white  matter. 

20.  Treat   a  minute  fibre  of  brain-substance  or  a 
bundle    of   nerve-fibres    under   the   microscope   with 
perosmic  acid,  and  notice  a  blue  reaction, 


90  BUTYRIC  ACID. 

21.  Search    for    amyloid    matter    by    the    process 
described  under  that  body. 

22.  In  some  diseases,  such  as  softening  of  the  brain, 
search  for/ree  glycero-phosphoric  acid.     This  "will  pass 
into  the  liquids  obtained  by  sodium  chloride,  process 
6,  and  by  baryta  water,  process  7.     The  sodium  chloride 
solution,  freed  from  caseine  and  albumen,  as  above, 
must  be  filtered,  neutralised  with  calcium  carbonate, 
evaporated    to    a    small    compass,    and    precipitated 
boiling  with  a  sufficient  volume  of  alcohol.     Dissolve 
the  precipitate  in  as  little  cold  water  as  possible,  and 
boil ;  calcium  glycero-pliosphate  will  separate,  and  must 
be  again  dissolved  and  thrown  down  by  boiling,  finally 
washed  with  a  very  little  hot  water,  then  with  alcohol, 
dried  at  100°  0.,   and   analysed.     It  should   contain 
60-47  %  of  Ca. 

23.  To   obtain    glycero-phosphoric   acid    from  the 
baryta  water  extract,  process  7,  take  the  mother  liquor 
of  kreatine  and  leucine,  remove  urea  by  oxalic  acid,  and 
subject  the  residual  fluid  to  the  treatment  described  in 
the  previous  paragraph. 

24.  The  albuminous  matters  which  remain  insoluble 
in  the  course  of  any  of   the  processes  of  extraction 
above  described,  will  yield    by  chemolysis  (e.  g.,  by 
boiling  with  dilute  sulphuric  acid)    leucine,  tyrosine, 
and    the    other     usual     decomposition     products     of 
albumen. 

Butyric  acid. — 1.  Produce  butyric  acid  from  sugaj, 
as  directed  under  lactic  acid,  but  allow  the  mixture  to 
stand  five  or  six  weeks.  The  calcium  lactate  is 


BILIARY   CALCULI.  91 

gradually  "converted  into  butyrate.  When  no  more 
gas  is  evolved  dilute  with  water,  precipitate  with 
sodium  carbonate,  filter,  evaporate  down  and  decom- 
pose with  rather  dilute  sulphuric  acid.  Separate  off 
the  oily  stratum  of  butyric  acid,  distil  it  with  a  little 
sulphuric  acid,  digest  with  fused  calcium  chloride  and 
again  distil,  rejecting  the  first  portions. 

2.  Distil  the  vomited  matters  or  intestinal  discharges 
of  cholera  patients   (rice  water)  with  sulphuric  acid, 
neutralise    the  distillate  with  soda,   evaporate  down, 
decompose    with    sulphuric    acid,    and    distil    again. 
Saturate   the   hot   distillate  with   hydra  ted  oxyde  of 
copper,  and  let  stand,  when  cupric  butyrate  will  crys- 
tallise, while  cupric  acetate  will  remain  in  solution. 

3.  Butyric  acid  boils  at   157°  0. ;    it   has  an   un- 
pleasant rancid  smell;  it  is   insoluble   in  water   and 
alcohol. 

4.  To  lead  acetate  solution  add  a  little  butyric  acid 
dissolved  in  water ;  an  oily  precipitate  of  lead  butyrate 
will  appear. 

5.  To  a  solution  of  potassium  or  sodium  butyrate 
add  cupric  sulphate ;   a   green   precipitate   of   cupric 
butyrate  will  be  formed  soluble  in  hot  water,  and  de- 
positing in  crystals  on  cooling. 

6.  Heat  a  butyrate  with  alcohol  and  sulphuric  acid. 
Butyric  ether,  having  a  characteristic  odour  of  pine- 
apples, will  be  evolved. 

Calculi)  biliary.  Systematic  analysis. — 1.  Heat  a 
portion  of  the  calculus  on  platinum  foil ;  it  burns  with 
a  clear  or  sooty  flame,  and  is  almost  entirely  consumed. 


92  BILIARY   CALCULI. 

Boil  a  portion  of  the  calculus  with  alcohol ;  it  is  dis- 
solved, and  on  cooling  deposits  crystals  of  cholesterine. 
These  features  characterise  the  pellucid  or  pure  chole- 
sterine calculus. 

2.  The  calculus  is  coloured  blackish  brown  or  green, 
and   contains  a  coloured  nucleus.     It  burns  like  the 
former  at  first,  but  is  with  difficulty  consumed,  leaving 
a  notable  amount  of  ash.    Extract  cholesterine  by  ether, 
and  test  the  coloured  residue  with  dilute  hydrochloric 
acid.    From  the  washed  residue  extract  Mlifuscine  with 
alcohol,  and  bilirubine  with  chloroform.     The  insoluble 
residue  on  combustion  and  the  hydrochloric  extract  on 
evaporation   will  yield  earths   and  their  phosphates, 
particularly  calcium   and  magnesium.      This   bearing 
characterises    mixed    calculi    with   prevalence    of  cho~ 
lesterine. 

3.  The    calculus    is    dark    red   or    brown,    rough, 
fissured,  without   fatty   feel,   and   easily   broken.     A 
portion  heated  on  platinum  foil  evolves  a  disagreeable 
odour  of  burnt  feathers  and  leaves  an  ash.     Treat  a 
portion  with  water  and  hydrochloric  acid  and  chloro- 
form at  the  same  time.     The  chloroform  will  become 
red  from  dissolved  bilirubine.     Evaporate  the  chloro- 
form solution  on  a  white  plate,  and  add  a  drop  of  red 
nitric  acid  to  the  yellow  residue,  and  observe  the  play 
of  colours  peculiar  to  the  colouring  matter  of  bile.    These 
reactions   characterise   the   calculi  mth  prevalence   of 
cholochrome9  which  occur  rarely  in  man,  but  are  the 
only  calculi  hitherto  observed  in  cows  and  oxen. 

4.  The  calculi  are  small  and  black  or  dark  green, 
and  insoluble  in  most  solvents,  except  boiling  nitric? 


BILIAEY   CALCULI.  93 

acid.  In  this  solution  water  produces  an  orange- 
coloured  deposit.  Neither  cholesterine,  nor  bilifuscine, 
nor  bilirubine,  can  be  extracted  from  them,  but  they 
contain  besides  the  coloured  peculiar  ingredient  much 
earthy  salt.  They  constitute  the  variety  known  as 
calculi  with  prevalence  of  modified  cholo  chrome,  and  are 
found  in  old  and  decrepit  persons. 

5.  Heat  a  portion  of   the  calculus,  it  evolves  the 
odour  of  burnt  feathers,  and  on  combustion  leaves  a 
slight  ash.     Treat  a  portion  with  alcohol  and  a  little 
sulphuric  acid,  and  observe  its  solution  in  the  alcohol. 
Treat  a  portion  of  the  calculus,  or  of  the  alcoholic 
extract  with  sulphuric  acid  and  sugar  as  directed  under 
cholic    acid,    a    violet    colour    is   produced.      These 
reactions  characterise  calculi  with  prevalence  of  biliary 
acids. 

6.  Heat  a  portion  of  the  calculus  and  it  will  evolve 
an  odour  of  burning  fat.     Treat  a  portion  with  acetic 
acid  and  boiling  alcohol  and  it  will  dissolve,  and  on 
cooling  deposit  fatty  acids.     Determine  the  melting- 
point  of  these,  and  test  their  reaction  with  a  boiling 
solution  of  phosphate  of  sodium.     The  calculus  may 
contain  biliary  pigments  :    Calculi   with  prevalence  of 
fatty  acids. 

7.  Heat  the  calculus  or  a  portion  and  observe  that  it 
is  merely  coloured,  hardly  contains  organic  matter,  and 
that  its  ash  almost  retains  the  shape  of  the  matter 
before  heating.     Add  hydrochloric  acid  to  the  ash,  or 
to  the  original  calculus,  and  it  will  dissolve  with  effer- 
vescence.    Over-saturate  the  solution  with  ammonia 
and  no,  or  scarcely  any,  precipitate  will  ensue.     Such 


94          INTESTINAL,  PROSTATIC,  AND  UEINARY  CALCULI. 

are  the   reactions   of  calculi  with  prevalence   of   car- 
bonate of  lime. 

Calculi,  intestinal. —  From  horses  fed  upon  bran. 
Saw  the  calculus  in  two  halves,  and  observe  nucleus. 
Examine  saw-meal  or  a  chip  of  the  hard  crystalline 
matter.  It  loses  water  and  ammonia  by  heating  to 
redness,  and  leaves  a  residue  easily  soluble  in  hydro- 
chloric acid,  and  reprecipitated,  on  standing  in  crystals, 
by  excess  of  ammonia.  .  The  calculus,  therefore,  consists 
mainly  of  ammonio-phosphate  of  magnesium,  with  which 
more  or  less  phosphate  of  calcium  is  mixed.  It  hardly 
contains  any  inorganic  matter. 

Calculi,  prostatic. — Minute  concretions,  from  the 
size  of  mustard  or  hemp  seeds  to  that  of  barley- 
corns. Dissolve  powder  in  acetic  acid,  and  observe 
evolution  of  carbonic  acid  gas.  Add  to  solution 
excess  of  ammonia,  and  observe  that  solution  remains 
clear ;  absence  of  phosphates  of  earths ;  if  solution 
forms  deposit  phosphates  of  earths  are  present.  If 
necessary  filter,  and  add  oxalate  of  ammonium;  a 
copious  precipitate  of  calcium  oxalate  will  ensue.  The 
calculi,  therefore,  consist  principally  or  entirely  of 
carbonate  of  calcium. 

Calculi,  urinary* — Systematic  analysis.  Powder  the 
calculus.  Heat  a  small  portion  of  the  powder  to 
redness  on  some  platinum  foil  and  observe  whether 
any  residue  is  left  which  will  not  burn  off. 

A.     In  case  it  leaves  a  fixed  residue,  take  a  small 


URINARY    CALCULI.  95 

portion  of  the  original  calculus,  'dissolve  in  concen- 
trated nitric  acid,  evaporate  to  dryness  on  a  water  bath 
in  a  white  porcelain  evaporating  dish  ;  dip  a  glass  rod 
into  the  strongest  ammonia,  and  bring  it  near  the 
residue  in  the  dish,  and  observe  whether  a  pink  colour 
is  produced  or  not. 

I.  A  pink  colour  is  produced,  proving  that  the  cal- 
culus contains  uric  add;  observe  whether  a 
portion  of  the  calculus  melts  on  being  heated. 

a.  It  melts — 

1.  And  communicates  a  strong   yellow  colour 
to   the   flame   of   a  spirit   lamp   or   Bunsen 
burner ;  Sodium  urate. 

2.  And   communicates   a  violet   colour   to  the 
flame,  giving  the  potassium  spectrum ;  Potas- 
sium urate. 

b.  It  does  not  melt;  dissolve  the  residue  left  after 
ignition  in  a  little  dilute  hydrochloric  acid,  add 
ammonia   till   alkaline,   and    then     ammonium 
carbonate  solution. 

1.  A  white  precipitate  falls  ;  Calcium  urate. 

2.  No    precipitate;    add    some    hydric     sodic 
phosphate  solution ;  a  white  crystalline  pre- 
cipitate falls ;  Magnesium  urate. 

II.  No  pink  colour  is  produced.  Observe  whether  a 
portion  of  the  calculus  melts  on  being  heated 
strongly. 

a*  It  melts  (fusible  calculus).     Treat  the  residue 
with   acetic   acid :    it    dissolves ;    add    to  the 


96  URINARY   CALCULI. 

solution  ammonia  in  excess ;  a  white  crys- 
talline precipitate  falls ;  Ammonia  magnesium 
phosphate.  In  case  the  melted  residue  is  in- 
soluble in  acetic  acid,  treat  with  hydrochloric 
acid;  it  dissolves.  Add  to  the  solution  am- 
monia ;  a  white  precipitate  indicates  Calcium 
.  phosphate. 

b.  It  does  not  melt;  moisten  the  residue  with 
water,  and  test  its  reaction  with  litmus  paper ; 
it  is  not  alkaline.  Treat  with  hydrochloric 
acid,  it  dissolves  without  effervescence.  Add 
to  the  solution  ammonia  in  excess ,  white  pre- 
cipitate; Calcium  phosphate.  Treat  the  cal- 
culus with  acetic  acid;  it  does  not  dissolve. 
Treat  the  residue  after  heating  with  acetic 
acid,  it  dissolves  with  effervescence ;  Calcium 
oxalate.  Treat  the  original  calculus  with  acetic 
acid,  it  dissolves  with  effervescence;  Calcium 
carbonate. 

B.  The  calculus  on  being  heated  does  not  leave  a 
fixed  residue.  Treat  a  portion  of  the  calculus  with 
nitric  acid,  evaporate  and  expose  to  ammonia  vapour 
as  before. 

I.  A  pink  colour  is  developed. 

a.  Mix  a  portion  of  the  powdered  calculus  with  a 
little   lime,  and  moisten  with   a  little   water;- 
ammonia  is  evolved  and   a  red   litmus   paper 
suspended    over     the    mass    is    turned    blue; 
Ammonium  urate. 

b.  No  ammonia;   Uric  acid. 


CASEINE.  97 

II.     No  pink  colour  is  developed. 

a.  But  the  nitric  acid  solution  turns  yellow  as  it 
is  evaporated,  and  leaves  a  residue  insoluble  in 
potassium  carbonate ;  Xanthine. 

b.  The    nitric   acid   solution    turns    dark   brown 
and    leaves    a    residue    soluble    in    ammonia; 
Cystine. 

Caseine. — 1.  Add  to  skimmed  milk  a  little  hydro- 
chloric acid,  wash  the  curd  with  water,  then  with  water 
acidified  with  hydrochloric  acid,  and  finally  with  plain 
water.  Dissolve  the  jelly  (caseine  hydrochlorate)  in  a 
large  quantity  of  water,  filter,  add  ammonium  car- 
bonate cautiously,  wash  the  precipitate  (free  caseine), 
exhaust  with  alcohol  and  ether,  and  wash  again  with 
water. 

2.  Dissolve  the  moist  caseine  thus  obtained  in  dilute 
hydrochloric    acid,    filter.       The    liquid    will    rotate 
polarised  light  to  the  left,  and  will  possess  the  pro- 
perties of  a  solution  of  albumen. 

3.  To  a  weak  solution  of  caustic  potash  add  moist 
jaseine  as  long  as  dissolved.     The  alkali  will  be  neu- 
tralized.      Filter     and    use    for    the    following    ex- 
periments : 

4.  Add  an  acid — the  caseine  will  be  precipitated,  but 
will  redis solve  in  excess  of  the  acid. 

5.  Boil  the  solution.     It  will  not  coagulate,  but  an 
insoluble  pellicle  will  form  on  the  surface. 

6.  Add  solution  of  a  calcium  salt,  or  of  magnesium 
sulphate.     A  precipitate  will  appear  on  boiling. 

7.  Add    solution   of  lead  acetate,  cupric    sulphate, 

7 


98  CEREBfttC   ACID. 

alum,  mercuric  chloride,  or  tannic  acid.     A  precipitate 
will  appear  in  the  cold. 

8.  Dissolve  moist  caseine  in  acetic  acid.    Add  solution 
of  potassium  ferrocyanide  or  chromate ;  the  caseine  will 
be  precipitated. 

9.  Dissolve  moist  caseine  by  warming  in  concentrated 
hydrochloric  acid.     The  solution  will  have  a  fine  violet 
colour. 

10.  Expose  moist  caseine  to  the  air.     It  will  putrefy, 
and  yield  similar  products  to  fibrine  (see  fibrine). 

11.  Boil  caseine  with  caustic  potash.     Ammonia  is 
evolved.     To  the  liquid  add  lead  acetate.      A  black 
precipitate    will    prove    the    presence    of    potassium 
sulphide. 

Cerebric  acid  (Fremy's). — 1.  Brain  is  cut  into  small 
pieces,  treated  repeatedly  with  boiling  alcohol,  and  left 
for  some  days  in  alcohol,  to  remove  water,  then 
pressed,  pounded,  and  extracted  with  boiling  ether, 
which  dissolves  cerebric  acid  and  other  substances. 
Distil  off  the  ether,  and  exhaust  the  residue  with  cold 
ether  to  remove  cholesterine  and  leci thine  (q.  v.).  Boil 
with  absolute  alcohol  acidified  slightly  with  sulphuric 
acid,  and  filter  hot.  The  deposit  formed  on  cooling 
must  be  washed  with  cold  ether  to  remove  oleo -phos- 
phoric acid  (q.  v.),  and  the  remaining  cerebric  acid 
purified  by  recrystallisation  from  boiling  ether. 

2.  White  crystalline  granules,  swelling  up  like 
starch,  but  not  dissolving,  in  boiling  water,  insoluble 
in  cold,  soluble  in  hot  alcohol  and  ether.  From  the 


CEKEBRINE.  TO 

emulsion  in  water  it  is  precipitated  by  neutral  salts, 
such  as  sodium  chloride. 

3.  Heated  on  platinum  foil  it  quickly  decomposes, 
burning  with  a  peculiar  smell,  and  leaving  a  difficultly 
combustible  charcoal,  and  at  last  a  white  residue  of 
phosphoric  acid. 

4.  Treat  cerebric  acid  with  concentrated  sulphuric 
acid — a   red    solution  will  be   formed.      Add  a  little 
sugar — a  deep  purple  colour  will  be  developed,  similar 
to  that  obtained  with  bile  acids  (q.  v.). 


AaBC 


HH' 


Spectrum  of  cerebric  acid  reaction. 

5.  Dissolve   in  boiling   alcohol,    and  add  sufficient 
alcoholic  potash   or  soda.     A  voluminous  white  pre- 
cipitate (alkaline  cerebrate,  Fremy)  is  formed,  and  on 
further  boiling  will  partially  dissolve,     Filter  hot — a 
white  body  remains  on  the  filter,  which  after  drying 
dissolves    in    boiling    alcohol,    leaving  only   a    scanty 
yellow  resinous  residue,  and  on  cooling  deposits  pure 
Cerebrine  (Miiller) . 

6.  Fremy 5s  cerebric  acid  and  Liebreich's  protagon; 
are  probably  compounds,  or  mixtures  in  atomic  pro- 
portions, of  lecithine  and  cerebrine,  as  appears  from  the 
above  decomposition  and  the  following  comparison  of 
their  elementary  composition. 


100  CEREBRINE. 


0 

Fremy's 
Cerebric  acid. 

...     66-7     ... 

Liebreich's 
Protagon. 

66-2       K7-4 

Miiller's 
Cerebrine. 

68-45 

Diakonow'a 
Lecithine. 

...       64-27 
11-40 

H  ... 

N  ... 
P  
O 

...     10-6    ... 

11-1 

11-9  . 
2-9  . 
1-5  . 

11-27 

...      2-3     ... 

2-7 

4-61    .. 

1-8 

...     19-5 

1-1 

18-9 

3-8 

16-3 

15-67 

18-73 

100-0 

100-0 

100-0 

100-00 

100-00 

Cerebrine  (Miiller),  C17H33N03. — 1 .  Brain  is  made  into 
a  thin  milk  with  excess  of  baryta  water  (or  lead  acetate 
solution),  heated  till  it  coagulates,  the  coagulum  boiled 
with  alcohol,  and  the  solution  filtered  hot.  The  volu- 
minous white  flaky  precipitate  which  forms  on  cooling, 
is  exhausted  with  cold  ether,  and  recrystallized  from 
boiling  spirit  as  long  as  any  trace  of  a  yellowish 
resinous  body  remains  insoluble  on  solution.  The 
product  is  pure  cerebrine,  having  the  following  pro- 
perties ; 

2.  White,  loose,  very  light,  tasteless  and  inodorous 
powder,  neutral  to  vegetal  colours,  insoluble  in  water, 
cold   alcohol,  and  ether.      Under  the   microscope   it 
consists  of  small,  nearly  globular  particles. 

3.  Heated  on  platinum  foil,  it  turns  brown,  emitting 
a  smell  of  burnt  horn,  then  melts  and  burns  with  a 
red  flame,  leaving  a  black  swollen  charcoal,  which  on 
long  heating  burns  away  entirely  without  residue. 

4.  It  is  insoluble  in  cold  or  hot  baryta,  potash  or 
ammonia. 

5.  Heated  with  soda  lime  it  evolves  ammonia. 

6.  Unaltered  in  cold  water,  it  swells  up  in  hot  to  a 
thin,  light  turbid  emulsion,  permanent  on  cooling  and 
unchanged  by  acids,  alkalies,   or  metallic    salts.     On 


CEREBRINE.  101 

evaporation  a  residue  remains,  soluble  in  hot  alcohol, 
and  precipitated  on  cooling  as  unaltered  cerebrine. 

7.  Hydrochloric,  nitric,  and  phosphoric  acids  in  the 
cold  effect  no  change.      On  boiling  with  hydrochloric 
the  body  turns  reddish-violet,  then  brown,  decomposing 
and  depositing  a  brown  resin  insoluble  in  acids  and 
alkalies. 

8.  In   cold   oil  of  vitriol  it   dissolves  with  a  dark 
purple  colour ;  the  solution  mixed  with  water  becomes 
colourless,  and  deposits  a  viscid  yellowish  substance. 
This  reaction  resembles  that  of  bile  acids. 

9.  Heated  in  a  retort  with  nitric  acid  it  evolves  red 
fumes,  and  gives  a  clear  distillate.     From  the  liquid 
in    the   retort   drops   of   yellow   oil   separate,    which 
solidify  on  cooling,  and,  after  being  freed  from  nitric 
acid  by  washing  with  water,  dissolve  in  boiling  alcohol, 
and  are  deposited  on  standing  in  white  fatty  granules. 
These,  after  repeated  crystallisation,  appear  as  a  white 
waxy  mass,  tolerably  soluble  in  hot  or  cold  alcohol, 
or  ether,  reacting  in  alcoholic  solution  as  a  feeble  acid, 
and  consisting,  under  the  microscope,  of  clear  fatty 
globules   without    a    trace    of    crystallisation.      This 
compound  contains  12.92  %  H,  and  75.52  %  0 ;  hence, 
probably,  all  the  nitrogen  has  been  removed.     Heated 
on  platinum  foil  it  melts  readily,  and  burns  with  a 
bright  flame  and  a  smell  of  burning  fat. 

10.  Cerebrine  is  free  from  sulphur.     When  oxydised 
by  fuming  nitric   acid,  or  by  fusing  with  potassium 
nitrate  and  potash,  it  gives  no  phosphoric  reactions 
with  any  of  the  tests.     When  phosphorus  is  found,  it 
arises  probably  from  contamination  with  lecithine. 


102  CHOLESTEEINE. 

,  11.  It  is  decomposed  at  80°  C;  hence  the  analyses 
must  be  made  on  a  substance  dried  at  75°,  at  which 
temperature  no  decomposition  occurs. 

Cholesterine,  C26HM)0. — 1.  Powder  a  human  biliary 
calculus,  boil  with  alcohol  and  allow  to  cool ;  the  cho- 
lesterine  crystallises  out  in  colourless  laminae  and 
rhombic  plates. 

2.  Extract  some  brain  substance  with  ether,  boil  the 
ethereal  extract  with  alcohol,  allow  to  cool ;  the  cho- 
lesterine crystallises  out,  but  mixed   with   potassium 
cerebrate    and    phosphate.      Treat    with    ether    and 
evaporate ;  the  cholesterine  will  crystallise  out. 

3.  Cholesterine  is  white,  tasteless,  without  smell ;  it 
is  insoluble  in  water,  it  dissolves  with  difficulty  in  cold 
but  easily  in  boiling  alcohol. 

4.  Mix  some  cholesterine  with  a  little  dilute  sulphuric 
acid,  warm  gently,  add  gradually  some  concentrated 
sulphuric  acid  :  the  cholesterine  will  soften  and  acquire 
a  deep  red  colour  without  evolving  any  gas. 

5.  Heat  some  cholesterine  cautiously  in  an  inclined 
glass  tube  ;  it  will  fuse,  boil  and  distil,  and  be  con- 
densed as  a  solid  crystalline  mass  in  the  cold  part  of 
the  tube. 

6.  Enclose  cholesterine  with  any  free  fatty  acid  in  a 
glass  tube,  seal  by  fusion  and  heat  the  tube  for  a  long 
time  to  150°.     The  cholesterine  will  combine  with  the 
fatty  acid  and  form  a  cholesteride  or  body  similar  to 
the  glycerides  or  ordinary  fats. 

Cholic  acid,  C^H^Og, — 1.  Boil  glykocholic  or  tauro- 
cholic  acid,  or  purified  bile,  with  excess  of  hot  con- 


CHOLIC   ACID.  103 

centrated  baryta  water  for  some  time,  allow  to  cool, 
separate  off  the  crystalline  mass  and  heat  it  with 
hydrochloric  acid.  The  cholic  acid  will  then  separate 
as  a  glutinous  resin.  Allow  to  stand,  decant  the 
solution  of  baryum  chloride,  wash  the  resinous  mass 
well  with  water,  dissolve  in  boiling  alcohol,  and  leave 
the  solution  to  crystallise.  Separate  the  colourless 
glassy  crystals. 

2.  Ascertain  their  slight  solubility  in  water,  greater 
solubility   in   ether,    and   great    solubility   in   boiling 
alcohol. 

3.  Expose  them   to  dry  air  under  the  receiver  of 
the  air-pump  over  sulphuric  acid ;  observe  that  they 
lose  water  of  crystallisation  and  disintegrate. 

4.  Take  a  small  quantity  of  the  acid  and  treat  with 
a  drop  of  solution  of  cane-sugar,  adding  concentrated 
sulphuric  acid  until  the  acid  is  entirely  dissolved.     On 
standing  for  a  short  time  the  mixture  will  assume  a 
purple  colour.     This  test,  known  as  Pettenkofer's,  is 
also  produced  by  the  glyko-  and  tauro-cholic  acid,  and 
these  yield  it  probably  by  virtue  of  their  decomposition 
liberating  cholic  acid.     See  spectrum,  p.  74. 

5.  Boil  cholic  acid  with  nitric  acid  for  a  long  time, 
and  obtain  cholesteric  acid  from  the  mother  liquor.     As 
the  same  acid  is  obtained  from  cholesterine  by  the  same 
process,  it  is  probable  that  cholic  acid  and  cholesterine 
have  the  same  radical  in  common. 

Chondrine. — 1.  Boil  cartilage  from  a  young  subject 
in  water  in  an  open  vessel  during  twenty- four  hours, 
or  in  a  Papin's  digester  under  pressure  at  120°  (/. 


104  CHONDEINE. 

during  four  hours,  and  observe  that  it  dissolves,  and 
that  a  solution  of  chondrine  is  formed,  which  on  cooling 
gelatinises. 

2.  To  the  hot  solution  of  chondrine  add  acetic  acid, 
decant  the  fluid    from  the  precipitated  chondrine,  and 
mix  it  with  alcohol  and  ether.     The  dry  product  is 
pure  chondrine. 

3.  Compare  a  solution  of  ordinary  gelatine  with  the 
chondrine  solution,  and  observe  that  the  former  is  not 
precipitated  by  acetic  acid. 

4.  To  a  pure  watery  solution  of  chondrine  add  some 
chloride  or  acetate  of  sodium,  then  acetic  acid,  and 
observe  that  the  precipitation  of  chondrine  does  not  take 
place. 

5.  Place  a  watery  or  alkaline  solution  of  chondrine  in 
the  polaroscope,  and  observe  that  it  rotates  towards  the 
left;    the   alkaline    solution   the   more   so,   the   more 
alkali  it  contains. 

6.  Boil  with  sulphuric  acid  and  treat  the  acid  liquid 
as    described    under    leucine,    and   obtain  this   body. 
Observe  that  no  glykokM  can  be  obtained. 

7.  Boil   cartilage  or   chondrine   with   concentrated 
hydrochloric  acid  until   a   sample  after  having  been 
made   alkaline   reduces    Trommer's    copper    solution. 
Boil  the  mixture  with  litharge,  filter;  to  the  filtrate 
add  basic  lead  acetate  and  ammonia ;  isolate  the  pre- 
cipitate, decompose  it  with  hydrothion,  evaporate  to  a 
small    bulk.     The    syrup    obtained    is   fermentescible 
glucose. 

8.  To   a  solution   of  chondrine   in  hot  water  add 
alcohol :  the  chondrine  will  be  precipitated  in  flakes. 


CHONDRINE.  105 

9.  Add  sulphuric,  hydrochloric,  nitric,  or  phosphoric 
acid,  a  precipitate  will  at  first  form,  but  will  redissolve 
in  excess  of  the  acid. 

10.  Add  arsenic,  oxalic,  acetic,  tartaric,  citric,  or 
lactic  acid,  or  carbonic  acid  water ;  a  precipitate  will 
fall,  insoluble  in  excess  of  acid. 

11.  Add  solution  of  ferrous  sulphate,  ferric  chloride, 
alum,  cupric  sulphate,  mercurous  or  mercuric  nitrate ; 
a  white  precipitate  is  formed  in  each  case. 

12.  Add   solution    of    potassium    ferrocyanide,    or 
mercuric  chloride.     No  precipitate  will  be  produced. 

13.  Drop   a   piece    of   dry   chondrine   into    strong 
nitric  acid  and  boil.     It  will  turn  yellow  and  finally 
dissolve. 

Chyle. — 1 .  Collect  some  white  chyle  from  the  chyle 
vessels  of  the  intestine  of  a  freshly  killed  animal  by  means 
of  finely  drawn  out  glass  tubes  containing  rarefied  air. 
Observe  that  the  chyle  coagulates  after  some  minutes 
or  hours,  and  can  be  isolated  from  the  tube  as  a  white 
cylinder  of  solid  matter. 

2.  Collect  some   chyle  by  means  of  a  repetition  of 
this  process  in  a  small  vessel.     Keep  this  covered  to 
prevent  evaporation ;  observe  that  the  chyle  coagulates 
and  on  standing  separates  into  white  fibrine,  and  into 
a  white  turbid  serum,  of  strongly  alkaline  reaction. 

3.  Collect  chyle  from  the  thoracic  duct  by  means  of 
a  suction  syringe,  or  from  living  animals  by  a  canula 
inserted  by  means  of  a  skilful  operation. 

4.  Observe  microscopically  that  it  contains  white  and 
red  blood-corpuscles  and/&£  granules. 


106  CHYLE. 

5.  Separate  the  coagulum  from  chyle  and  observe 
that  it  has  all  the  properties  offibrine. 

6.  Treat  the  serum  with  ether;  it  will  not  become 
clear.     Add  acetic  acid  or  caustic  potash  to  the  serum, 
and  the  ether  will  then  extract  all  the  fat. 

7.  The  addition  of  acetic  acid  in  sufficient  quantity 
to  the  serum  of  chyle  causes  a  precipitate  of  caseine. 

8.  Boil   the    serum   acidified   with    acetic  acid  and 
filtered  from  the  caseine,  and  observe  that  the  albumen 
is  precipitated. 

9.  In  the  filtrate  prove  the  presence  of  peptones  by 
the  reactions  indicated  under  Chyme. 

10.  Evaporate  the  filtrate  to  an  extract,  and  pre- 
cipitate all  peptones  by  absolute  alcohol.     Evaporate 
the  alcohol  from  the  filtrate.     Remove  fats  by  extrac- 
tion with  ether.     Then  extract  by  means  of  ether  to 
which  some  sulphuric  acid  has  been  added.     The  ether 
leaves  lactic  acid  on  evaporation,  to  be  purified  and 
tested  as  shown  under  that  paragraph. 

11.  Examine  the  extract  for  glucose  by  Trommer's 
alkaline  copper-solution. 

12.  With  the  fats  extracted  under  10  some  urea  is 
extracted.     Separate   this   by   water   from   the   ether 
residue  and  test  with  nitric  and  oxalic  acid. 

13.  Burn  the  extract  of  chyle  and  analyse  the  alka- 
line ash.     Observe  its  great  similarity  to  the  ash  of  the 
serum   of  blood;    it   contains    little  iron   and   phos- 
phoric acid,  with  lime  and  magnesia,  but  a  considerable 
amount  of  chlorine  and  alkalies,  in   the   latter   soda 
prevails. 


CHYME.  107 

Chyme. — 1.  Subject  chyme  to  dialysis,  and  use  the 
dialysed  liquid,  after  evaporation  to  a  small  bulk,  for 
the  following  tests,  or 

2.  Obtain  peptones  from  fibrine,  albumen,  syntonine, 
or  gluten  by  artificial  digestion  with  pepsine  and  dilute 
hydrochloric   acid,   and  use  the   resulting  liquids  for 
these  tests. 

3.  Boil  the  solution  ;  it  is  not  coagulated. 

4.  Add  pure  taurocholic  or  glykocholic  acid;  in  each 
case  a  precipitate  is  immediately  produced. 

5.  Observe    that    the    solutions   turn    the    ray    of 
polarised  light  towards  the  left. 

6.  Precipitate  the  solution  with  absolute  alcohol, 
the  white  flakes  of  precipitated  peptone  are  again  soluble 
in  very  dilute  alcohol. 

7.  Add    Trommer's   copper   solution  to   chyme    or 
peptone,  and   observe   that  it   forms   a  purple  fluid. 
Boil,  and  if  a  red  precipitate  ensues  glucose  is  present 
in  the  chyme. 

8.  Add    cupric     sulphate,    ferric     chloride,     dilute 
mineral  acids  to  peptones,  and  see  that  no  precipitates 
ensue. 

9.  Add  chlorine,  iodine,  tannin,  corrosive  sublimate, 
mercuric  or  mercurous  nitrate,  silver  nitrate,  neutral 
or  basic  lead  acetate,  and  observe  that  the  peptones 
give  a  precipitate  with  each  of  these  reagents. 

10.  Boil    peptone    with    mercurous    and    mercuric 
nitrite  and  nitrate  with  ultimately  a  slight  excess  of 
nitric  acid,  and  observe  that   a   red  precipitate  and 
solution  results. 

11.  Ascertain  the  composition  of  any  peptone  pro- 


108  CRUENTINE. 

duced  by  process  6,  to  be  almost  equal  to  tlie  original 
substance  from  which  it  was  produced  by  artificial 
digestion. 

Connective  tissue. — 1.  Boil  connective  tissue  with 
water.  It  will  swell  up  and  at  last  dissolve.  The 
filtered  solution  will  have  the  properties  of  a  solution 
of  gelatine  (q.  v.). 

2.  Treat  with  acetic  acid ;  it  will  swell  up  and  be- 
come transparent.  Add  water  and  boil.  It  will 
dissolve.  To  the  solution  add  potassium  ferrocyanide. 
No  precipitate  will  ensue. 

Corpora  lutea.     See  Ovario-luteine. 

Cruentine. — 1.  Boil  the  blood-corpuscles,  purified  as 
in  the  preparation  of  hsematine,  with  sulphuric  acid. 
The  brown-red  flakes  of  cruentine  which  form  in  the 
liquid  jnust  be  washed  with  water  till  neutral. 

2.  Dissolve  the  flakes  in  sulphuric  acid.  The  spec- 
trum will  show  three  bands. 


AaBCD  EbF  G  HH 


Spectrum  of  sulphate  of  cruentine. 


3.  Treat  a  portion  of  the  dried  flakes  with  ether  or 
chloroform.  The  red  chloroform  solution  has  a  spec- 
trum of  four  bands  and  a  powerful  rose-red  fluoresence. 


AaBC        D 


CRUENTINE. 
Eb        F 


109 


HH' 


Spectrum  of  neutral  fluorescent  cruentine. 

4.  Treat  a  portion  of  the  flakes  already  extracted 
with  chloroform,  with  alcohol.  It  will  dissolve  almost 
entirely,  and  the  spectrum  of  the  solution  will  show 
five  bands. 


AaBC 


Eb 


HH' 


Neutral  five-banded  cruentine  in  alcohol. 

Add  ammonia  till  alkaline,  one  band  will  disappear 
and  the  others  slightly  change  their  position  and  size. 
5.  Cruentine  dissolved  in  ammonia  shows  four  bands. 


AaBC 


HH' 


Spectrum  of  alkaline  cruentine. 

When   treated   with   the   ferrous   tartrate    solution 
described  under  hematine,  it  is  reduced  and  now  shows 


110  CRUENTINE. 

three   bands.     Shaking   with   air   re-oxydises   it,  and 
restores  the  former  spectrum. 


AaBOD  EbF  G  HH 


Spectrum  of  reduced  cruentine. 

6.  Treat  the  chloroform  solution  obtained  in  2 
with  hydrochloric  acid  and  water.  "Warm  the  solution 
till  clear.  The  spectrum  will  show  three  bands.  Add 
excess  of  ammonia  and  warm.  The  three  bands  are 
unaltered. 


A  a  EC 


Hydrochloric  product  of  fluorescent  cruentine. 

7.  Boil  the  flakes  obtained  in  1  with  much  alcohol 
and  filter  hot.  On  cooling  red  flakes  will  be  deposited. 
Filter,  wash  with  alcohol,  and  dissolve  them  in  dilute 
hydrochloric  acid,  and  observe  spectrum  of  two  bands. 


AaBCD  EbF  G  HH 


Spectrum  of  cruentme  Irydrochlorate. 


CYSTINE.  Ill 

Neutralise  with  carbonate  of  sodium,  wash  precipi- 
tate, and  dissolve  in  some  carbonate  of  sodium. 
Observe  that  the  spectrum  has  the  same  two  bands  as 
the  hydrochloric  acid  solution. 

Cystine,  C3H6NS03. — 1.  A  urinary  calculus  containing 
cystine  (see  Calculi)  is  powdered,  digested  with  am- 
monia, filtered,  and  the  filtrate  allowed  to  evaporate  and 
to  crystallise.  The  crystals  must  be  washed  with  water. 
They  are  insoluble  in  water  and  alcohol. 

2.  Heat  a  little  powdered  cystine  with  potash  solution 
till  dissolved,  add  acetic  acid  in  slight  excess.     The 
cystine  will  be  slowly  deposited  in  neutral  six-sided 
laminae.     Examine  microscopically. 

3.  Dissolve   a   small   quantity  of   cystine  in  dilute 
hydrochloric,    nitric,    or   sulphuric    acid.     Evaporate 
the   solution  and  set  aside  to  crystallise.      Grouped 
acicular   crystals  of   a  cystine  salt  will  gradually  be 
formed. 

4.  To  the  solution  in  acid  obtained  in  the  foregoing 
experiment    add   ammonium  carbonate.     The  cystine 
will  be  precipitated  as  a  white  powder. 

5.  Heat  some  dry  cystine  in  a  tube.     It  will  give  off 
a  thick,  fetid  oil,  hydrocyanic  acid,  and  ammonia,  and 
leave  a  porous  charcoal. 

6.  Fuse  with  caustic  potash  in  a  tube.     An  inflam- 
mable gas  will  be  evolved  forming   sulphurous  anhy- 
dride when  burned.     Dissolve  the  residue  in  water  and 
add   lead   acetate;    a  black   precipitate    will    appear, 
proving  the  presence  of  sulphur. 

8.  Heat  on  platinum  foil.     A  peculiar,  disagreeable 


112  DEXTEINE. 

odour  will  be  given  off,  and  the  cystine  will  burn  off 
without  melting,  evolving  a  smell  of  hydrocyanic  acid. 

Dentine. — 1.  The  main  portion  of  the  substance  of 
the  teeth,  covered  outside  by  the  enamel.  The  struc- 
ture is  tubular.  It  contains  animal  matter,  calcium 
carbonate  and  phosphate,  and  a  trace  of  magnesium 
phosphate. 

2.  The  enamel  contains  calcium  carbonate,  phosphate, 
and  fluoride,  magnesium  phosphate,  and  a  very  little 
organic  matter. 

Dextrine,  C12H10010. — 1.  Take  20  grammes  of  starch, 
mix  with  30  c.c.  of  water.  Dilute  5  grammes  of  con- 
centrated sulphuric  acid  with  30  c.c.  of  water  and  add 
the  dilute  acid  gradually  to  the  starch  paste.  Mix 
well  and  heat  for  some  time  in  a  water  bath  at  90°  C. 
"When  cold  add  alcohol ;  the  dextrine  will  be  precipi- 
tated. 

2.  Dextrine  cannot  be  crystallised ;  it  is  soluble  in 
water,  but  insoluble  in  absolute  alcohol. 

3.  Dissolve  a  portion  in  water  and  add  a  drop  of 
dilute  tincture  of  iodine;    the  solution  remains   un- 
coloured.     Starch,  under  similar  circumstances,  would 
be  coloured  a  deep  blue. 

4.  Add  to  an  aqueous    solution  of  dextrine,    some 
solution  of  caustic  potash  and  a  drop  of  a  very  dilute 
sulphate  of  copper  solution ;  boil ;  the  copper  salt  will 
be  reduced,  the  liquid  darkens,  and  finally  a  bright  red 
precipitate  of  copper  suboxyde  is  precipitated. 

5.  It  rotates  polarised  light  to  the  right.     Boil  dex- 


ELASTIC   TISSUE.  113 

trine  with  dilute  sulphuric  acid,  it  will  be  converted  into 
glyJcose. 

Elastic  Tissue. — 1.  From  the  neck-band  and  middle 
coat  of  arteries  and  veins.  Remove  extraneous 
matters  by  boiling  with  alcohol,  ether,  water,  strong 
acetic  acid,  dilute  potash,  water,  dilute  hydrochloric 
acid  (10%),  and  again  with  water  and  dry  at  100°  C. 
The  residue,  elastine,  is  a  brittle,  yellowish,  fibrous, 
mass,  swelling  up,  but  insoluble  in  water,  insoluble  in 
alcohol,  ether,  and  acetic  acid.  Examine  as  follows  : 

2.  Soak   in   dilute   acetic   acid;  it  will  recover  its 
elasticity  and  fibrous  appearance. 

3.  Boil  a  long  time  with  water;  it  will  remain  in- 
soluble and  will  not  be  converted  into  gelatine.     (See 
Connective  Tissue.) 

4.  Digest   with   strong   caustic   potash ;     a   brown 
solution  will   be   formed.     Neutralise   with    sulphuric 
acid  and  add  tannic  acid,  a  precipitate  will  ensue.     No 
other  acid  will  produce  a  precipitate,  and  the  solution 
will  not  form  a  jelly  when  evaporated. 

5.  Chemolyse  by  boiling  with  dilute  sulphuric  acid ; 
it  will  yield  nearly  the  same  products  as  albumen  (q.  v.). 

6.  Heat  on  platinum  foil ;  it  will  burn  away  entirely 
without  ash. 

7.  Fuse  with  caustic  potash,  dissolve  in  water,  and 
add  potash-acetate  of  lead.     No  black  precipitate  will 
form,  proving  absence  of  sulphur. 

Excretine.  C78H156S02  (Marcet). — 1.  Extract  dried 
human  fasces  with  boiling  absolute  alcohol,  on  evapo- 

8 


114  IVECES. 

rating  the  extract  and  allowing  to  stand,  if  possible  at 
0°  C.,  silky  crystals  of  excretine  are  deposited. 
2.  Excretine  is  very  soluble  in  ether. 

Excretolic  Acid  (Marcet). — 1.  Obtain,  as  directed 
under  fseces  and  purify  by  dissolving  in  hot  alcohol, 
and  allowing  to  deposit  on  cooling. 

2.  It  is  an  olive -coloured  substance  with  an  offensive 
odour  of  faeces,  very  soluble  in  hot  alcohol  and  in  ether, 
slightly  soluble  in  cold  alcohol,  insoluble  in  water.     The 
alcoholic  solution  has  an  acid  reaction. 

3.  Heat  on  platinum  foil ;  it  will  burn  with  a  lumi- 
nous flame,  evolving  a  fascal  smell. 

Fceces. — 1.  Dry  and,  ascertain  proportion  of  water 
(73  to  75%). 

2.  Exhaust  a  quantity  of  dried  fseces  with  boiling 
alcohol.     (The  residue  will  be  insoluble  in  water  and 
ether    and    will   consist   mainly  of  food-remains  and 
insoluble  inorganic  matters.)      Filter,  and  allow  the 
solution  to  stand.     A  deposit  containing  a  peculiar  fat 
called  excretolic  acid  (q.  v.)  will  gradually  form. 

3.  Filter  again,  add  milk  of  lime  ;  a  brown  precipi- 
tate will  fall.     Dry  the  precipitate  and  extract  it  with 
ether ;    the  ether  on  evaporation  will  leave  excretine 
(q-v.),  which  may  be  purified  by  crystallisation  from 
alcohol. 

4.  The  portion  insoluble  in  ether  must  be  boiled 
with     dilute    hydrochloric    acid,     and    'the   resulting 
fatty  acid  (generally  margaric)  washed  with  water  and 
treated  as  directed  under  fats  (q.v.). 


FATS.  115 

5.  Another  portion  of  this  insoluble  matter  should 
be  digested  with  dilute  sulphuric  acid,  and  the  solution 
examined  spectroscopically  for  products  of  decomposi- 
tion of  hematine  or  other  matters. 

6.  Digest  the  dried  faeces  in  chloroform :  no  cholo- 
pha3ine  can   be    extracted,    showing  that  the  biliary 
matters,  if  present,  had  been  changed  in  composition 
in  passing  through  the  intestine. 

7.  Distil   the  fresh  undried  faeces  with  dilute  sul- 
phuric acid ;  a  fetid  distillate  will  pass  over,  containing 
volatile  acids  (q.v.)  and  an  essential  oil. 

8.  Burn  dried  faeces  and  analyse  ash.     Notice  pre- 
dominance of  potash  over  soda. 

Fats.  Extraction  and  separation  of  animal  fats. — 1 . 
Exhaust  the  substance  (concentrated  to  an  extract,  if 
liquid)  with  boiling  90%  alcohol  containing  enough 
sulphuric  acid  to  decompose  any  soaps  that  may  be 
present,  evaporate  the  mixed  filtered  extracts  to  near 
dryness,  treat  with  three  or  four  volumes  of  ether, 
allow  to  stand  for  some  time  with  frequent  agitation, 
decant  or  filter. 

2.  The  matter  insoluble  in  cold  ether  may  contain 
cerebric  acid,  palmitin,  and  stearin.     Boil  with  caustic 
potash  solution  till  saponified,  separate  out  the  soaps 
by  adding  solid  potassium  chloride,  collect,  press,  dry 
at  100°  C.,  reduce  to  as  fine  a  powder  as  possible,  and 
digest  with  cold  alcohol.      Potassium   cerebrate    will 
remain  undissolved. 

3.  "Wash  the  cerebrate  with  cold  alcohol,  decompose 
by   boiling   alcohol    containing    sulphuric     acid,    and 


116  FATS. 

decant  or  filter.  On  cooling,  the  cerebric  acid  will  be 
deposited,  and  must  be  washed  with  cold  ether  and 
purified  by  recrystallising  from  boiling  ether. 

4.  Warm    the    alcoholic    solution    of   stearate  and 
palmitate,  add  cautiously  alcohol  containing  sulphuric 
acid  till  all    the  potassium  has  been  precipitated  as 
sulphate.     Filter,  evaporate  down,  and  separate  the 
stearic     and    palmitic    acid    by    crystallisation     from 
absolute   alcohol,    in   which    the   former    is    the   less 
soluble. 

5.  The   ethereal   solution    must    be  evaporated    to 
dryness,  boiled  with  caustic  potash  till  saponified,  and 
decanted  from  undissolved  cholesterine. 

6.  The  cholesterine  is  purified  by  crystallisation  from 
boiling  alcohol. 

7.  The   soap,  containing  oleic  and  margaric   acids, 
must    be    salted    out    by    potassium    chloride,   again 
dissolved  and  salted  out,    dried,    powdered,  and   di- 
gested with  cold  alcohol,  in  which  oleate  is  the  more 
soluble.     From  the  salts  thus  separated  the   acids  are 
obtained  by  sulphuric  acid  as   above.     The  margaric 
acid  may  be  purified  by  crystallisation  from  alcohol. 
Digest  the  oleic  acid  at  100°  C.  with  half  its  weight  of 
finely-powdered   lead   oxyde,  mix  the  resulting  mass 
with  two  volumes   of  ether,  allow  to  stand ;    decant 
from  any  undissolved  matter,  shake  the  solution  with 
enough  dilute  sulphuric  acid  to   combine   with  nearly 
all  the  lead,  separate  off  the  solution  of  oleic  acid  in 
ether,  and  drive  off  the  ether  by  distillation. 

Fibrine  of  blood. — 1 .  Beat  briskly  a  quantity  of  fresh- 


FIBRINE    OF   BLOOD.  117 

drawn  blood  with  a  bundle  of  twigs.  Remove  the 
fibrine  adhering  to  the  twigs,  put  it  in  a  bag,  tie  the 
mouth  of  the  bag  tightly  round  a  tap,  and  allow  water 
to  run  through,  frequently  kneading  the  mass,  until 
colourless.  The  substance  thus  obtained  is  fibrine 
mixed  with  white  blood-corpuscles. 

2.  Keep  moist  fibrine   in   a   covered   beaker   in   a 
warm   place.     It   will  gradually  liquefy  and  give    off 
an   offensive    smell,    owing   mainly  to    butyrate    and 
valerate  of  ammonia.     The    mass   mixed   with  water 
will  coagulate  on   heating,    showing  the  presence  of 
albumen.      Ammonium  sulphide  will  also  be  formed, 
and  will  blacken  a  slip  of  paper  moistened  with  lead 
acetate. 

3.  Extract  with  boiling  water,  evaporate  to  dryness, 
and    digest    with    strong    alcohol.        Evaporate    the 
alcohol  solution  to  dryness  ;  the  residue  will  give  the 
reactions   of  leucine   (q.v.).     The  portion  insoluble  in 
alcohol  must    be    treated   with    a  little  concentrated 
hydrochloric  acid,  and  the  acid  solution  precipitated 
by  excess  of  strong    sodium   acetate  solution.      The 
precipitate  will  give  the  reactions  of  tyrosine  (q.v.). 

4.  Dry    a  portion   and  heat  on  platinum  foil.      It 
takes  fire,    giving   out  a  smell  of  burnt  feathers,  and 
leaves  a  porous  charcoal. 

5.  Dissolve  fibrine  in  dilute  caustic  potash  at  60°  C., 
filter,  and   add   slowly  acetic  or    tribasic  phosphoric 
acid.     A  precipitate  will  be  formed,  soluble  in  excess 
of  acid. 

6.  Boil    with    caustic    potash,     ammonia    will    be 
evolved.      Potassium  sulphide  will  be  formed  in  the 


118 


FLUOPITTINE. 


liquid  and    will   give  a    black    precipitate    with  lead 
acetate. 

7.  Concentrated    hydrochloric     acid     on    warming 
dissolves  it  with  a  violet  colour. 

8.  Add  nitric  acid ;  the  fibrine  will  turn  yellow  and 
dissolve. 

9.  Add  concentrated  acetic  or  tribasic  phosphoric 
acid ;    a    gelatinous    mass,  soluble  in  water,   will  be 
produced. 

10.  Tannic  acid  precipitates  it  from  its  solutions, 
and  forms  with  it  in  the  solid  state  a  hard  imputres- 
cible  mass. 

11.  Place    a  portion  of  fibrine  in  dilute  hydrogen 
peroxyde ;    it  will   become    covered   with  bubbles  of 
disengaged  oxygen.     Prove  that  the  gas  is  oxygen. 

Fluopittine. — A  resinous  body  obtained  from  fluores- 
centine  (q.v.).,  showing  the  following  remarkable 
spectrum. 


AaBC 


HH' 


Spectrum  of  fluopittine. 

Fluor escentine. — An  organic  base  obtained  in  decom- 
posing albuminous  substances  by  chemolysis. 

Formic  acid  CH203. — 1.  Obtain  from  animal  sub- 
stances, as  described  under  Acetic  acid,  1  and  2.  Formic 
acid  boils  at  101°  C.,  giving  an  inflammable  vapour. 


GASTRIC   JUICE.  119 

2.  To  sodium  formiate  solution  add  a  little  ferric 
chloride.       The  same    effect  will   appear  as  with  an 
acetate. 

3.  Heat    sodium   formiate   with    mercuric  chloride 
solution.     A  precipitate  at  first  of  mercurous  chloride 
and  finally  of  metallic  mercury  will  appear. 

4.  Add  silver  nitrate  solution  and  heat.     Metallic 
silver  will  be  deposited  as  a  black  powder  or  a  mirror- 
like  coating. 

5.  Heat    a    formiate    with    dilute    sulphuric    acid. 
Formic  acid,  recognized  by  its  odour,  will  be  set  free. 

6.  Heat  a  formiate  with  sulphuric  acid  and  alcohol. 
Formic  ether,  of  a   peculiar   pleasant  odour,  will  be 
evolved. 

7.  Heat   a  formiate   in  powder  with    concentrated 
sulphuric  acid :    carbonic    oxyde    will    be    given    off, 
and  will  burn  with  a  blue  flame.      The  mixture  will 
not  blacken. 


Gastric  juice. — 1.  Gastric  juice,  obtained  through  a 
gastric  fistula  or  by  means  of  the  stomach  pump  or 
gastric  syphon,  must  be  filtered  and  examined  as 
follows  : 

2.  Boil ;    no  precipitate  will  be  formed.     Test  the 
reaction  with   litmus ;  the  reaction   is   acid.      Notice 
taste,  smell,  and  appearance. 

3.  Add  alcohol  of  90%  strength,  collect  the  preci- 
pitate of  pepsine  (see  pepsine). 

4.  Distil  some  gastric  juice.     The  first  distillate  will 
be  acid,  but  will  give  no  precipitate  with  silver  nitrate. 


120  GELATINE,    OR   OSSEINE. 

The  last  portions,  however,  will  contain  hydrochloric 
acid. 

5.  Test  the  juice  for  lactic  acid  (see  Lactic  acid). 

6.  Evaporate  a  quantity  of  the  juice  to  dryness,  and 
burn.     Examine  the  ash  for  phosphates  and  chlorides, 
and  for  potash,  soda,  lime,  magnesia,  and  iron.     More 
sodium  will  be  found  than  potassium. 

7.  Digest  pieces  of  caseine  or  coagulated  albumine  in 
gastric  juice ;  they  will  dissolve.     Boil  the  solution  ;  it 
will  not  coagulate.     Add  potassium  ferrocyanide,  lead 
acetate,  dilute  alcohol,  or  a  mineral  acid ;  no  precipi- 
tate will    appear.      Add   solution  of    tannic    acid   or 
mercuric  chloride ;  a  precipitate  will  be  formed. 

Gelatine,  or  Osseine. — 1.  Digest  clean  bones  with 
hydrochloric  acid  mixed  with  nine  parts  of  water. 
Replace  the  acid  once  or  twice  by  fresh  more  dilute 
acid,  until  nothing  more  is  dissolved.  Wash  the 
remaining  mass  repeatedly  with  water  to  remove  acid, 
and  dry  at  a  steam  heat. 

2.  Treat  with  cold  water ;  it  will  swell  up  but  not 
dissolve.     Boil,  and  a  solution  will  be  formed.     Use 
the  solution  for  the  following  experiments. 

3.  Add  a  solution  of  tannic  acid ;  the  gelatine  will 
be  precipitated.     No  other  acid  will  precipitate  it. 

4.  Add  solutions  of  alum,  ferric  sulphate,  potassium 
ferrocyanide,  cupric   sulphate,  or  lead   acetate.      No 
precipitate  will  be  produced. 

5.  Add  mercuric  chloride  solution  in  excess.      A 
white  precipitate  will  form. 

6.  Boil  one  part  of  dry  gelatine  with  four  parts  of 


GLYCEEOPHOSPHORIC   ACID.  121 

sulphuric  acid  and  twelve  parts  of  water  for  thirty- six 
hours.  Add  excess  of  milk  of  lime  or  baryta;  boil 
and  strain.  Acidify  very  slightly  with  sulphuric  acid, 
filter,  and  evaporate  to  a  low  bulk.  The  granular 
crystals  which  form  on  standing  must  be  removed, 
boiled  with  alcohol,  filtered,  and  the  solution  evapo- 
rated to  crystallisation.  The  crystals  will  consist  of 
glykokoll  recognised  by  the  usual  tests. 

7.  Boil  gelatine  with  strong  caustic  potash  till  com- 
pletely decomposed ;  neutralise  with  sulphuric  acid, 
and  evaporate  to  a  low  bulk.  From  the  residue  warm 
alcohol  will  extract  leucine,  which  may  be  recognised  by 
the  usual  tests  (see  leucine). 


Globulins. — 1.  Pound  a  number  of  crystalline  lenses 
with  water,  filter,  evaporate  the  filtrate  in  vacuo  over 
sulphuric  acid,  and  wash  the  product  with  ether  and 
dilute  alcohol.  Examine  as  follows  : 

2.  Treat  with  water ;    it  will  dissolve.     Filter  and 
heat  the  solution.     At  73°C  it  will  become  opalescent ; 
at  93°  it  will  coagulate. 

3.  Pass  through  the  aqueous  solution  a  current  of 
carbonic  anhydride;  a  precipitate  will  fall  soluble  in 
pure  water. 

4.  The  other  reactions  are  similar  to  albumine  (q.  v.). 

Glycerophosphoric  acid,  C3H9P06. —  1.  Obtain  by 
synthesis  as  follows  : — Digest  glycerine  with  an  excess 
of  glacial  phosphoric  acid,  mix  with  water,  neutralise 
with  baryum  carbonate,  then  with  baryta  water,  filter, 


122  GLYOEROPHOSPHORIC   ACID. 

precipitate  the  baryum  with  just  sufficient  sulphuric 
acid,  and  evaporate  the  nitrate  in  vacuo. 

2.  From  Brain.     See  Brain. 

3.  From  Lecithine.     See  Lecithine. 

4.  From  Egg -yelk.     Dry  in  a  water   bath,   extract 
with  boiling  alcohol,  evaporate  to  dryness,  remove  the 
oil  by  draining  and  pressure  between  paper  at  a  tem- 
perature of    80°C,  and  boil   the   viscid    residue    for 
twenty-four  hours  with  dilute  caustic  potash.     Add  to 
the  solution  acetic  acid  in  slight  excess,  and  filter ; 
precipitate  the  filtrate   with  lead  acetate,  decompose 
the   washed   precipitate    with   hydrothion,  evaporate 
cautiously,  and   treat   with   a   little    silver   oxyde   to 
remove  hydrochloric  acid,  and  the  filtrate  with  hydro- 
thion to  remove  silver.     After  driving  off  the  hydro- 
thion by  evaporation  neutralise  the  liquid  with  calcium 
carbonate,  filter,  and  concentrate.     Calcium  glycero- 
phosphate  will  crystallise  out,  and  may  be  purified  by 
recrystallisation.     The  acid  may  be  isolated  by  preci- 
pitation with  oxalic  acid  and  evaporation  in  vacuo. 

5.  It  is  a  very  acid,  gummy,  uncrystallisable  liquid, 
very  soluble  in  water  and  alcohol.      The  somewhat 
concentrated  aqueous  solution  decomposes  by  heating 
into  phosphoric  acid  and  glycerine. 

6.  Heated  on  platinum  foil  it  burns  with  difficulty, 
leaving  a  charcoal  containing  phosphoric  acid. 

7.  The  baryum  salt  is  very  soluble  in  water,  and  is 
precipitated  by  alcohol. 

8.  The   calcium    salt  crystallises    in  white    pearly 
scales,  of  the  formula  C3H7CaP06,  decomposes  above 
170°C.      Boiling    with    lime    water    resolves    it   into 


GLYKOGEN.  123 

calcium  phosphate,  and  glycerine.  It  is  more  soluble 
in  cold  than  in  hot  water,  and  is  precipitated  by 
alcohol. 

9.  The  lead  salt  is  insoluble  in  water  and  alcohol. 

GlyJcocholic  acid,  C36H45N06. — 1.  Add  to  some  fresh 
ox-bile  a  solution  of  neutral  lead  acetate,  filter  off  the 
precipitate,  heat  it  with  boiling  alcohol,  filter  hot,  pass 
hydrothion  into  the  filtrate  while  hot,  and  filter  off  the 
sulphide  of  lead.  Allow  the  filtrate  to  cool ;  it  will 
solidify  into  a  white  crystalline  mass  of  glykocholic  acid, 
which,  after  washing  with  water,  is  perfectly  pure. 

2.  Add  to  a  small  granule  of  glykocholic  acid  or  of 
its  salts  a  drop  of  cane  sugar  solution,  and  then  con- 
centrated sulphuric  acid  in  drops,  agitating  the  solution, 
and  preventing  overheating ;  a  violet  or  purple  liquid 
will  be  formed. 

3.  To  glykocholate  of  sodium  dissolved  in  absolute 
alcohol  add  ether  ;  a  glutinous  precipitate  will  ensue, 
which  on  standing  under  the  ether  alcohol  will  trans- 
form into  crystals. 

4.  To  a  glykocholate  dissolved  in  water  add  hydro- 
chloric acid ;  a  glutinous  deposit  of  amorphous  glyko- 
cholic acid  will  ensue. 

5.  Boil  some  glykocholic  acid  with  excess  of  baryta 
water  ;  cholate  of  baryum  will  crystallise  after  cooling, 
and  glylcokoll  will  remain  in  solution  to  be  extracted  as 
stated  under  that  substance. 

Glykogen,    C6H1005    (Hepatine). — 1.    Mince    a   fresh 
liver  and  boil  with  a  small  quantity  of  water.     Strain 


124  GLYKOKOLL. 

and  press.  Precipitate  the  filtrate  with  four  or  five 
times  its  volume  of  90%  alcohol.  Yellowish  white 
flocks  will  be  precipitated.  These  are  well  washed 
with  alcohol  and  then  boiled  for  half  an  hour  or  an 
hour  with  solution  of  caustic  potash;  dilute  the 
solution  with  a  small  quantity  of  water  and  add  four 
or  five  times  its  volume  of  90%  alcohol.  The  glykogen 
is  precipitated  and,  by  washing  with  alcohol  is  obtained 
tolerably  pure. 

2.  Mince  a  liver  and  boil,  &c.,  as  before,  allow  the 
extract  to  cool,  and  add  glacial  acetic  acid,  when  the 
glykogen  will  be  precipitated ;  filter  off  and  dry.     Grly- 
kogen  is  a  white  mealy  powder ;  it  exhibits  no  definite 
structure  under  the  microscope. 

3.  It  is  soluble  in  water,  insoluble  in  alcohol. 

4.  Boil  glykogen  with  some  dilute  hydrochloric  acid, 
it  will  be  transformed  first  into  dextrine  and  finally  into 
grape  sugar.     This  transformation  can  be  detected  by 
the  reducing  action  of  sugar  on  alkaline  copper  solu- 
tion.    (See  Dextrine,  &c.) 

5.  Boil    an    aqueous    solution    with    a    solution    of 
caustic  potash  to  which   a  drop   of  dilute  solution  of 
copper  sulphate  has  been  added.     The  copper  salt  will 
not  be  reduced. 

6.  Add    to    an  aqueous    solution   a  drop  of  dilute 
tincture  of  iodine  ;  a  violet-red  colour  is  produced. 


Glykokoll,  C2H5N03.  —  1.  Boil  glue  with  caustic 
potash.  Ammonia  is  evolved  in  large  quantity.  Add 
sulphuric  acid  till  the  liquid  is  neutral ;  evaporate, 


GLYKOSE.  125 

separate  the  potassium  sulphate,  which  will  crystallise 
out ;  evaporate  the  clear  liquid  to  dryness.  Exhaust 
the  residue  with  hot  alcohol ;  allow  to  cool ;  the  gly- 
kokoll will  crystallise  out. 

2.  Boil  hippuric  acid  for  half  an  hour  with  strong 
hydrochloric  acid,  dilute  the  liquid  with  water,  and 
allow  to  cool.     The  benzoic  acid  will  separate  in  crys- 
tals ;  decant  the  clear  liquid,  treat  with  ammonia,  and 
evaporate    on  a  water  bath;   wash  the  dried  residue 
with  alcohol;    the  glykokoll   is   left   in  a  crystalline 
powder. 

3.  Glykokoll  crystallises  in  hard  granular  crystals ; 
it  has  a  sweet  taste. 

4.  It  dissolves  with   difficulty  in  water ;  it  is  inso- 
luble in  absolute  alcohol. 

5.  Pass  nitrous  acid  into  a  solution  of  glykokoll. 
The  whole  of  the  nitrogen  is  evolved,  and  glykollic 
acid  (C2H403)  is  formed  soluble  in  ether.     Shake  the 
liquid  with  some  ether ;  allow  to  stand ;  draw  off  the 
ethereal  layer   with  a   syphon;    evaporate,  when  the 
crystallised  glykollic  acid  is  left. 

6.  Boil  an  aqueous  solution  of  glykokoll  with  copper 
oxyde ;  a  copper  salt  is  obtained,  which  crystallises  out 
in  blue  crystals,  turning  green  when  dried  at  100°C. 

GlyJcose  or  Glucose,  C12H34013. — 1.  Boil  twenty 
grammes  of  starch  with  eighty  c.c.  of  water,  add  one  to 
two  grammes  of  concentrated  sulphuric  acid,  and  boil  for 
twenty-four  hours,  adding  water  as  the  solution  eva- 
porates. Add  calcium  carbonate  to  neutralise  the  free 
acid,  allow  to  stand,  decant,  and  evaporate  the 


126  GLYKOSE. 

decanted  liquor  to  a  thin  syrup,  from  which  in  a  few 
weeks  the  glucose  will  crystallise  out. 

2.  Heat  some  glucose  with  a  solution  of  bichromate 
of  potash  and  sulphuric  acid  in  a  test  tube  furnished 
with   a    cork    and    delivery  tube ;    pass  the    evolved 
vapours  into  a  solution  of  nitrate  of  silver;   formic 
acid  will  be  evolved,  which  will  reduce  and  blacken  the 
silver  solution. 

3.  Add  some  cold  concentrated  sulphuric  acid  to 
glucose ;  the  latter  will  dissolve  without  blackening ; 
cane  sugar  blackens. 

4.  Dissolve   some   glucose    in    water,   add    caustic 
potash  solution,   and  a    drop   or  two  of   very  dilute 
copper  sulphate  solution;  after  long  standing  in  the 
cold,  or  immediately  on  boiling,  the  copper  salt  will  be 
reduced,  and  a  bright  red  precipitate  of  copper  sub- 
oxyde  falls. 

5.  Add  a  solution  of  glucose  to  a  solution  of  silver 
nitrate  and  heat  gently  ;  the  silver  salt  is  reduced,  and 
metallic  silver  is  deposited  either  as  a  black  powder  or 
as  a  mirror-like  coating. 

6.  Dissolve  two  parts  of  ferricyanide  of  potassium 
and  one  part  of  hydrate  of  potassium  in  water,  warm, 
and  add   aqueous  solution  of  glucose.     The  solution 
will  be  decolorised.     Neither  cane  sugar  nor  dextrine 
give  this  reaction. 

7.  To  an  aqueous  solution  of  glucose  add  a  concen- 
trated solution  of  common  salt,  and  allow  to  stand ; 
crystals  of  chloride  of  sodium  and  glucose  separate. 
These  crystals  will  be   formed  if  diabetic    urine   be 
evaporated  and  allowed  to  stand. 


GUANINE.  127 

8.  Diabetic  sugar  is  identical  with  dextro -glucose 
above  described. 

Guanine,  C5H6N50. — 1.  Boil  500  grm.  of  Peruvian 
guano  with  milk  of  lime  till  the  liquid  has  turned  from 
brown  to  greenish  yellow,  filter,  neutralise  with  hydro- 
chloric acid,  and  allow  to  stand  some  hours.  Wash 
the  deposit,  treat  with  boiling  hydrochloric  acid,  decant 
the  clear  liquid  from  the  undissolved  uric  acid,  set 
aside  to  crystallise,  and  purify  the  crystals  by  re- 
crystallising  from  HC1.  Finally  precipitate  by  ammonia, 
wash  with  water  and  dry. 

2.  Pure   guanine    is    a   white,    neutral    amorphous 
powder,  insoluble  in  water,  soluble  in  strong  acids  and 
alkalies.     The  hydrochlorate  crystallises  in  thin,  light 
yellow  needles,  which  lose  water  at  1 00°  C.,  and  acid  at 
200°  0. 

3.  Dissolve  a  little  guanine  in  hot  nitric  acid.     On 
cooling,  long,  very  fine,  interlaced  crystals  of  nitrate 
will  form. 

4.  Treat    solution   of  guanine   hydrochlorate   with 
ammonia  oxalate.     Crystals  of  guanine  oxalate  will  be 
produced. 

5.  Mix   hot    saturated  solution  of  guanine  in  HC1 
with   excess  of  hot   concentrated  PtCl4,  evaporate  to 
one  half  and  allow  to  cool.     Wash  with  alcohol  and 
ether  the  yellow  needles  formed,  and  dry  in  vacuo  over 
sulphuric  acid.     Weigh  a  small  portion,  ignite  in   a 
weighed   crucible,  and  weigh    the  residue  of   spongy 
platinum.     The  salt  should  contain  35'17  of  platinum. 
Formula  C5H5N50,  HCl+PtCl4+2H2O. 


128  HEMATINE. 

Hair. — 1.  Notice  structure  under  microscope. 

2.  Digest    with    concentrated    warm    hydrochloric 
acid ;  it  will  very  slowly  dissolve  to  a  violet  solution. 

3.  Heat  with  nitric  acid,  it  will  turn  yellow  and  in 
great  part  dissolve. 

4.  Boil  with  strong  caustic  potash,  it  will  dissolve. 
Add  to  the  solution  potash-lead  acetate,  a  black  pre- 
cipitate of  sulphide  will  ensue,  proving  the  presence  of 
sulphur. 

5.  Heat  on  platinum  foil ;  it  will  burn  with  an  odour 
of  horn  and  leave  a  swollen  charcoal,  and  finally  about 
1%  of  ash  containing  iron. 

6.  Chemolyse  by  means  of  sulphuric  acid.     Leucine, 
tyrosine,  &c.,  will  be  obtained. 

Hematine. — 1.  Dilute  one  volume  of  saturated  sodium 
chloride  solution  with  fifteen  volumes  of  water.  Add 
one  volume  of  blood,  freed  from  fibrine  by  beating  and 
filtered  through  a  cloth.  Mix  well  and  allow  to  stand 
in  ice  and  water  till  the  corpuscles  have  settled. 
Decant  the  liquid  and  wash  them  with  the  same  quan- 
tity of  sodium  chloride  as  before.  Repeat  this  opera- 
tion a  third  and  fourth  time.  Shake  the  corpuscles 
with  water  and  ether,  separate  off  the  ether,  and  to 
the  red  watery  solution  add  basic  lead  acetate  solution 
in  slight  excess,  filter  off  the  precipitate,  and  remove 
excess  of  lead  by  a  little  potassium  carbonate.  To  the 
filtrate  add  potassium  carbonate  in  powder  till  the 
colouring  matter  separates,  filter  off  the  flakes,  press 
them  strongly,  break  the  mass,  and  exhaust  with  strong 
alcohol.  To  the  extract  add  alcoholic  solution  of  tar- 


HEMATINE. 


129 


taric  acid  to  a  slightly  acid  reaction,  filter,  and 
evaporate  at  60°  C.  to  one  tenth  of  its  bulk.  On 
standing  minute  crystals  of  hematine  are  deposited,  and 
may  be  purified  by  washing  successively  with  ether 
and  cold  water. 

2.  Examine  the  hematine  under  the  microscope,  it 
will  be  found  to  consist  of  rhombic  crystals. 

3.  Hematine  is  insoluble  in  water,  alcohol  and  ether 
when  neutral,  but  soluble  in  water  containing  caustic 
alkali,  or  in  acid  or  alkaline  alcohol. 

4.  Dissolve  some  hematine    in  alcohol  and   a   little 
sulphuric  acid.     The  spectrum  will  show  four,  under 


AaBC         D  Eb        F 


HH' 


Spectrum  of  four-banded  hematine. 


HH' 


AaBC         D  Eb        F 


Spectrum  of  five-banded  hematine, 


certain  circumstances  five,  bands.  Render  the  solution 
alkaline  by  caustic  potash.  The  spectrum  will  show 
only  one  broad  band.  Acid  will  restore  the  spectrum. 

9 


130 

AaBC         D 


HIPPURIC   ACID. 
Eb        F  G 


HIT 


Spectrum  of  pure  alkaline  hematine. 

5.  Dissolve  hematine  in  water  with  a  little  caustic 
potash.  To  a  solution  of  ferrous  sulphate  add  tartaric 
acid  and  then  ammonia  till  alkaline.  Pour  a  little  of 
the  clear  mixture  into  the  hematine  solution,  and 
examine  the  spectrum.  It  will  show  two  bands. 
Shaking  with  air  will  restore  the  former  spectrum. 


AaBC 


Spectrum  of  reduced  hematine. 

Hippuric  Acid,  C9H9N03. — 1.  Evaporate  the  fresh 
urine  of  horses  or  cows  which  have  been  kept  in  the 
stable  for  a  day  or  two  previous  to  ^  or  -g-  of  its 
original  volume,  and  add  an  excess  of  hydrochloric 
acid.  After  standing  the  hippuric  acid  is  thrown 
down  as  a  yellowish-brown  precipitate. 

2.  Filter  or  decant  the  liquid  and  purify  the  crude 
hippuric  acid  as  follows : — Boil  with  milk  of  lime  and 
filter ;  precipitate  the  nitrate  with  sodium  carbonate, 
boil,  filter,  add  solution  of  chloride  of  lime,  filter, 
add  an  excess  of  hydrochloric  acid.  The  hippuric  acid 
will  finally  be  precipitated  in  a  colourless  condition. 


HYPOXANTHINE  OR  SAKKINE.  131 

3.  Prepare  from  urine    thus  : — Evaporate   it   to   a 
syrup,  add    some  hydrochloric  acid,   and  shake   in  a 
stoppered  bottle  with  its  own  volume  of  ether ;  allow 
to   stand    one   hour,  then   add   •£$  of   its  volume    of 
alcohol ;  allow  to  stand  a  short  time  ;  remove  the  upper 
ethereal  layer  with  a  syphon.       Shake   this    ethereal 
extract  with  a  small  quantity  of  water ;  allow  to  stand ; 
remove  the  ethereal  layer    as    before    and    evaporate. 
The  hippuric  acid  will  be  obtained  in  crystals  usually 
of  a  yellowish-brown  colour.     This  colour  can  be  re- 
moved by  treatment  with  animal  charcoal. 

4.  Recrystallise  the  acid  from  boiling  water,  in  which 
it  is  easily  soluble.     Observe  its  slight  solubility  in  cold 
water,  and  easy  solubility  in  alcohol. 

5.  Melt  it  in  a  glass  tube  and  let  it  consolidate  by 
cooling.    Then  heat  again  to  fusion  and  dry  distillation . 
Observe  the  irritating  vapours  of  benzoic  acid,  and  a 
sublimate  of  the  same,  and  a  charcoal  left  in  the  bottom 
of  the  tube. 

6.  Boil  hippuric  acid  for  half  an  hour  with  hydro- 
chloric acid.     It  will  be  split  up  into  glykokoll   and 
benzoic    acid.        Separate    both    as    described    under 
glykokoll. 

7.  To  a  solution  of  neutral  hippurate  add  solution  of 
ferric  chloride.     A   cinnamon- coloured    precipitate   of 
ferric  hippurate  will  be  formed. 

Hypoxanthine  or  Sarlwne,  C5H4N40. — 1.  The  mother 
liquor  of  xanthine  hydrochlorate,  obtained  as  under 
Xanthine,  is  evaporated,  and  another  crop  of  crystals 
removed  (sarkine  salt  containing  xanthine).  The 


132  INOSIC   ACID. 

mother  liquor  of  this  will,  on  further  evaporation, 
yield  nearly  pure  sarkine  salt.  Purify  by  recrystallisa- 
tion,  dissolve  in  hot  caustic  potash,  add  ammonium 
chloride,  filter  if  necessary,  pass  carbonic  acid  in  excess 
through  the  solution,  collect,  and  wash  the  precipitate 
of  sarkine. 

2.  Its  reactions  are  those  of  xanthine,   except   its 
greater  solubility  in   hydrochloric  acid,  and  the   fol- 
lowing : 

3.  To  a  dilute  solution   of  hypoxanthine  in   nitric 
acid    add    silver  nitrate;    a  copious  white  precipitate 
will  be  produced  (see  Xanthine  5). 

Inosic  acid,  C5H8N206. — 1.  Take  the  mother  liquor 
obtained  in  the  preparation  of  kreatine  (see  Kreatine) 
from  flesh.  Concentrate  and  mix  with  alcohol  till  it 
has  a  milky  consistence,  allow  to  stand  and  crystallise. 
Pour  off  the  liquid,  dissolve  the  crystals  in  hot  water, 
add  a  solution  of  baryum  chloride ;  crystals  of  baryum 
inosate  are  deposited  on  cooling.  Separate  these 
crystals,  dissolve  in  a  little  boiling  water,  and  add 
sulphuric  acid  as  long  as  a  precipitate  falls ;  allow  to 
stand,  decant,  and  evaporate  the  clear  liquid,  when 
inosic  acid  will  be  left  as  an  uncrystallisable,  syrupy 
mass. 

2.  Inosic  acid  is   easily  soluble   in  water ;    alcohol 
precipitates  it  from  aqueous  solution;  it  is   insoluble 
in  ether. 

3.  Add  to  an  aqueous  solution  of  inosic  acid  a  solu- 
tion of  copper  sulphate ;  a  bluish-green  precipitate  falls 
soluble  in  ammonia. 


INOSITE.  133 

4.  Heat  a  portion  of  inosic  acid,  or  an  inosate  on 
platinum  foil ;  it  will  decompose,  giving  off  the  odour 
of  roast  meat. 

Inosite,  C6H1306. — 1.  Mince  the  muscular  portion  of 
the  heart ;  add  water,  allow  to  stand  for  some  time, 
frequently  stirring  the  mass.  Separate  the  residue  and 
press.  Boil  the  nitrate  with  a  little  acetic  acid,  evapo- 
rate to  one  tenth  of  its  bulk,  precipitate  with  a  solution 
of  neutral  lead  acetate,  and  filter.  Mix  the  filtrate 
with  basic  lead  acetate :  a  precipitate  falls  of  impure 
inosite.  Wash  the  precipitate,  and  decompose  by 
passing  sulphuretted  hydrogen ;  filter  off  the  precipi- 
tated lead  sulphide.  Evaporate  the  filtrate  to  a  low 
bulk ;  separate  any  crystals  which  may  be  formed,  and 
mix  the  clear  liquid  with  alcohol  until  a  turbidity  is 
produced  :  crystals  of  inosite  will  be  deposited. 

2.  Inosite   dissolves   in   water ;    it   is   insoluble   in 
absolute  alcohol  and  ether ;  it  has  a  sweet  taste. 

3.  Heat  inosite  on    some  platinum  foil;    it   melts, 
swells  up,  evolving  gas  which  burns  with  a  pale  blue 
flame  ;  it  then  chars  and  burns  with  a  luminous  flame. 

4.  Evaporate  a  solution  of  inosite  in  dilute  nitric 
acid   nearly   to   dryness.     Moisten    the   residue   with 
ammonia  and  a  little  calcium  chloride  solution ;  evapo- 
rate, when  a  rosy-red  substance  will  be  left. 

5.  Boil  an  aqueous  solution  of  inosite  with  potash 
containing  a  drop  of  dilute  copper  sulphate  ;  the  copper 
salt  is  not  reduced. 

6.  Inosite  is  not  altered  by  boiling  with  dilute  acids 
or  alkalies. 


134  KREATININE. 

Kreatine,  C4H9N303. — 1.  Take  finely -chopped  meat 
free  from  fat,  or  chopped  cod-flesh ;  mix  well  with  an 
equal  weight  of  water,  squeeze  in  a  bag  of  strong  linen. 
Boil  the  extract,  filter  off  the  coagulated  albumen  and 
myochrome ;  treat  the  filtrate  with  baryta  water  until 
it  has  a  strongly  alkaline  reaction ;  filter,  evaporate  on 
the  water-bath  to  a  syrup,  allow  to  stand  in* a  warm 
place.  The  liquid  will  spontaneously  evaporate  and 
deposit  crystals  of  kreatine,  which  can  be  purified  by 
boiling  with  animal  charcoal  and  by  recrystallisa- 
tion. 

2.  Observe  the  insolubility  of  kreatine  in  cold  alcohol, 
and  its  slight  solubility  in  cold  water. 

3.  Boil  some  kreatine  with  a  large  excess  of  baryum 
hydrate ;  it  is  decomposed,  and  ammonia  is  evolved, 
the  vapour  turning  red  litmus  paper  blue.     This  is  due 
to  the  formation  and  decomposition  of  urea  on  the  one, 
and  the  formation  of  alanine  on  the  other  hand ;  both 
substances  can  be  obtained  from  the  fluid. 

4.  Dissolve    some    kreatine   in    some    hydrochloric, 
sulphuric,  or  nitric  acid ;  evaporate  at  a  gentle  heat ; 
crystals  are  deposited  which  are  soluble  in  alcohol,  and 
consist  of  a    compound    of  the  acid    employed   with 
kreatinme. 

5.  Dry  crystallised  kreatine  in  a  current  of  hot  air, 
and  observe  that  it  loses  water  of  crystallisation. 

Kreatinine,  C^HfNgO. — 1.  Take  fresh  human  urine, 
not  less  than  four  litres,  neutralise  it  with  milk  of  lime 
or  hot  saturated  baryta  water ;  add  a  solution  of 
calcium  chloride  as  long  as  a  precipitate  falls.  Filter 


KREATININE.  135 

and  evaporate  to  a  syrup,  allow  to  stand,  separate  the 
deposited  crystals,  and  add  to  the  syrup  one  twenty- 
fourth  of  its  weight  of  a  neutral  syrupy  solution  of 
zinc  chloride.  Allow  to  stand  three  or  four  days ;  the 
double  chloride  of  zinc  and  kreatinine  is  deposited  in 
crystalline,  warty  masses.  Wash  this  deposit  with 
water. 

2.  Dissolve  it  in  boiling  water  ;  add  hydrated  oxyde 
of  lead  until  the  fluid  has  an  alkaline  reaction.     Now 
add  three  times  as  much  oxyde  of  lead  as  has  been 
already  used,  and  boil  the  whole  for  some  time ;  filter. 
Boil  the  filtrate  with  some  good  animal  charcoal,  filter, 
evaporate  the  filtrate  to  dryness ;  a  crystalline  residue 
will  be  left.     Boil  the  crystals  with  eight  to  ten  times 
their  weight  of  alcohol,  allow  to  cool,  decant  the  clear 
liquid  from  any  crystals  of  Jcreatine  which  may  be  de- 
posited, and  evaporate  it,  when  crystals  of  Jcreatinine 
will  be  deposited. 

3.  Treat  fresh  urine  with  neutral  lead  acetate  as  long 
as  a  precipitate  is  produced  ;  evaporate  the  filtrate  to 
one  quarter  of  its  bulk,  and  treat  with  hydrothion  to 
remove  excess  of  lead.     Expel  hydrothion  by  boiling, 
and  add  corrosive  sublimate  to  the  liquid.     A  white 
precipitate  of  kreatinine  mercuric   chloride   will   fall. 
Filter,  wash,  and  decompose  with  hydrothion ;  evapo- 
rate filtrate  to  crystallisation,  when  kreatinine  hydro- 
chlorate  will  be  obtained. 

4.  Place  a  crystal  of  kreatinine  on  a  slip  of  moist 
turmeric  paper ;  it  will  produce  a  brown  spot ;  it  has, 
therefore,  an  alkaline  reaction. 

5.  Add  to  a  solution  of  corrosive  sublimate  a  solution 


136  KRYPTOPHANIC    ACID. 

of  kreatinine ;  it  will  produce  a  white  curdy  precipitate, 
which  is  soon  transformed  into  needles. 

6.  Add  to  an  aqueous  neutral  solution  of  zinc 
chloride  some  kreatinine  solution ;  a  crystalline  preci- 
pitate is  immediately  produced  in  the  form  of  warty 
grains.  2(C4H7N30)Zn012. 

Kryptophanic  acid,  C5H9N05,  or  C10H18N2010. — 1. 
Evaporate  fresh  urine  to  one  third ;  mix  with  excess 
of  milk  of  lime  or  baryta,  allow  to  stand  a  few  hours 
and  filter :  acidify  the  filtrate  with  acetic  acid, 
evaporate  to  a  syrup,  and  set  aside  to  crystallise. 
Separate  the  crystals  by  draining  and  pressure  from 
the  mother  liquor,  add  to  the  latter  five  times  its 
volume  of  alcohol  of  90%,  shake  well,  allow  to  stand 
for  five  minutes,  pour  off  the  liquid  and  wash  the 
precipitate  with  a  little  more  alcohol.  Warm  the 
sticky  deposit  to  drive  off  the  adhering  alcohol,  dis- 
solve in  a  small  quantity  of  water  and  filter.  To  the 
filtrate  add  twice  its  bulk  of  saturated  solution  of  lead 
acetate,  filter  from  the  dark  brown  precipitate,  mix  the 
filtrate  with  three  volumes  of  90  %  alcohol,  wash  with 
alcohol  the  nearly  white  precipitate  of  lead  Jcrypto- 
phanate,  lastly  wash  with  a  little  absolute  alcohol,  dry 
at  100°  C.,  and  weigh. 

2.  Mix  with  water  to  a  thin  cream,  and  for  every 
100  parts  of  the  dry  salt  add  an  equal  weight  of  sul- 
phuric acid  containing  25%  of  H2S04.  After  standing 
for  some  time,  with  frequent  agitation,  filter  and  test  a 
portion  of  the  filtrate  for  sulphuric  acid;  if  any  be 
present  precipitate  it  out  exactly  with  baryta  water, 


KRYPTOPHANIC   ACID.  137 

adding  no  excess,  and  filter.  Evaporate  the  filtrate  to 
a  thick  syrup,  precipitate  with  90%  alcohol,  wash  the 
precipitate  with  a  little  more  alcohol,  and  dry  the 
pure  kryptophanic  acid  at  a  very  gentle  heat,  or  in 
vacuo. 

3.  The  acid   is  very   soluble  in  water,    nearly  in- 
soluble in  alcohol,  insoluble  in  ether. 

4.  Dissolve  a  portion  in  water  :  the   solution  has  a 
pleasant  acid  taste.     Use  it  for  the  following  experi- 
ments. 

5.  Add  a  little  saturated  lead  acetate  solution :   a 
white  precipitate  will  fall,  redis solved  by  excess,  and 
again  precipitate  by  alcohol. 

6.  Add    copper    acetate :    a   green   precipitate  will 
form,  behaving  like  the  lead  compound. 

7.  Dry  a  portion  of  the  green  precipitate  at  100°  C., 
and  distil  with  a  small  quantity  of  water.     The  sub- 
stance will  turn  dark  green,  and  alcohol  will  be  found 
in  the  distillate,  proved  by  a  diminished  sp.  gr.  and 
by  its  reducing  a  drop  of  potassium  bichromate  and 
sulphuric  acid. 

8.  Add  copper  sulphate  in  excess,  then  excess  of 
caustic  potash  :  if  on  long  boiling  the  copper  is  reduced, 
the  acid  is  yet  impure ;  the  pure  acid  does  not  reduce 
copper  solution. 

9.  Add    mercuric    nitrate,    or    acetate,    or     silver 
nitrate.     A  white  precipitate  will  fall,  soluble  in  nitric 
acid. 

10.  Add  ammonio-nitrate  of  silver  :  the  solution  will 
become  dark  and  will  gradually  deposit  black  metallic 
silver. 


138  LACTIC   ACID. 

.11.  Heat  a  kryptophanate  in  the  solid  state  on 
platinum  foil :  acid  vapours  are  perceived  but  no 
iirinary  smell,  and  a  residue  of  difficultly  combustible 
charcoal  remains. 

12.  Add  baryum  or  calcium  chloride  :  no  precipitate. 
Add  ferric  chloride :  a  brown  precipitate  will  fall, 
soluble  in  excess  or  in  ammonia,  deposited  again  on 
boiling. 

Lactic  acid,  C3H603  (from  milk).— 1.  Take  300 
grammes  of  sugar,  3  grammes  of  tartaric  acid,  400 
grammes  of  sour  milk,  25  grammes  of  old  cheese,  and 
150  grammes  of  precipitated  chalk,  and  1250  cc.  of 
water  ;  allow  to  stand  in  a  moderately  warm  place,  about 
36°  C.,  from  ten  to  twelve  days.  Boil  the  semisolid 
mass  of  calcium  lactate  thus  produced  with  a  litre  of 
water  and  3  grammes  of  unslaked  lime ;  filter  while  hot 
and  gently  evaporate  the  filtrate.  Calcium  tartrate  is 
gradually  deposited  in  granules.  Collect  the  crystals 
and  press  between  filter  paper.  Dissolve  the  crystals 
in  twice  their  weight  of  water,  add  -£%  part  of  sul- 
phuric acid  and  filter  while  hot ;  add  to  the  filtrate  -x% 
of  zinc  carbonate,  boil  for  a  quarter  of  an  hour,  separate 
the  crystalline  zinc  salt,  dissolve  in  seven  to  eight  times 
their  weight  of  boiling  water,  pass  in  sulphuretted 
hydrogen,  filter  and  evaporate  to  a  syrupy  condition. 

2.  Boil  some  lactic  acid  with  nitric  acid;  the  lactic 
will  be  converted  into  oxalic  acid :  neutralise  the 
liquid  with  ammonia,  add  acetic  acid  and  a  little 
calcium  chloride  solution ;  calcium  oxalate  will  be 
precipitated. 


LECITHINE.  139 

3.  Lactic   acid    forms    numerous    crystalline    salts 
which  are  mostly  but  sparingly  soluble  in  water ;  they 
are  prepared  by  boiling  the  acid  with  a  carbonate. 

4.  E.g.  Boil  lactic    acid  with  zinc  carbonate,  filter 
hot ;  the  solution  will  on  cooling  deposit  crystals   of 
zinc  lactate. 

5.  Similarly  boil  lactic  acid  with  calcium  carbonate, 
when  calcium  lactate  will  be  formed. 

6.  Heat  the  syrupy  acid :  it  will  give  off  water,  and 
be  converted  into  the  anhydride,  which  fuses  below 
100°  C. ;  when  further  heated  to  260°  C.  it  is  converted 
into    lactide,   which    sublimates   in   white   crystalline 
plates. 


Lecithine,  C42H84NP09. — 1.  Preparation  of  Lecithine 
(from  egg-yelk).  Extract  the  yelk  with  a  mixture  of 
ether  and  alcohol,  distil  off  part  of  the  ether  from  the 
extract,  add  alcohol  as  long  as  turbidity  ensues  from 
the  separation  of  a  fatty  oil,  and  mix  the  clear  yellow 
solution  with  platinic  chloride  acidified  with  hydro- 
chloric acid.  A  copious  yellow  flocculent  precipitate 
of  a  double  salt  will  be  formed,  differing  greatly  from 
choline-platinic  chloride,  insoluble  in  water,  easily 
soluble  in  ether,  carbon  disulphide,  chloroform,  and 
benzol,  precipitated  from  these  solutions  by  alcohol  in 
yellow  flakes  agglutinating  on  agitation.  To  free  it 
from  fat,  it  must  be  dissolved  five  or  six  times  in  ether 
and  precipitated  each  time  by  alcohol.  In  vacuo  over 
sulphuric  acid  it  dries  without  losing  its  solubility  in 
ether,  but  at  100°  C.  it  blackens,  melts,  and  loses 


140  LECITHINS. 

weight,  as  much  as  5%  in  two  hours.     Its  formula  is 
(C43H83NP08C1)  PtCl4. 

2.  Cadmium  chloride  may  be  used  instead  of  platinic 
chloride.     The  yellow  flaky  precipitate  may  then  be 
washed  with  alcohol  and  ether  (in  which  it  is  little 
soluble),  and  can  be  more  easily  freed  from  fat  than  the 
platinic  chloride  compound.     It  is  soluble  in  alcohol, 
containing  hydrochloric  acid. 

3.  From    these    compounds,    after    removing    the 
metals     by    hydrothion,    lecithine    hydrochlorate     is 
obtained    on    evaporation    as    a    waxy    mass.      The 
chlorine  having  been  removed  by  silver  oxyde,  and  the 
silver    by    hydrothion,    a    homogeneous    translucent 
residue  of  free  lecithine  remains. 

4.  From  brain,  fyc.-9    it  may  be    extracted   by   the 
process  given  under  Gerebric  acid  and  Brain  (q.v.),  and 
purified  by  the  methods  described  above. 

5.  Lecithine  and   its   compounds    are   very    easily 
decomposed.      The    ethereal    solution  of  the  double 
platinum  salt  forms  on  standing  a  light  yellow  deposit 
of  choline-platinic  chloride.     The  alcoholic  solution  of 
lecithine  hydrochlorate  gives,   on  long  standing,  oily 
drops,  free  from  nitrogen  and  phosphorus,  and  forming 
a  soap  with  alkalies.      Free  lecithine  also  decomposes, 
slowly  in  the  cold,  rapidly  on  warming.     Boiling  with 
water  does  not  decompose  it  (Gobley),  but  addition  of 
dilute  mineral  acids  or  alkalies  causes  decomposition, 
with  separation  of  oleic9  margaric,  and  glycerophosphoric 
acid. 

6.  When    lecithine   hydrochlorate    is    poured    into 
boiling  baryta  water,  a  smeary  baryum  salt  separates, 


LECITHINE.  141 

while  the  filtrate  contains  choline  and  a  part  of  the 
glycerophosphoric  acid.  Eemove  free  baryta  by 
carbonic  anhydride,  and  extract  the  residue  with 
alcohol :  choline  hydrochlorate  dissolves,  and  may  be 
precipitated  by  platinic  chloride,  and  the  yellow  flaky 
precipitate  washed  with  alcohol.  By  crystallisation 
from  water  it  is  obtained  in  yellow  prisms  or  tables, 
closely  resembling  the  choline-platinic  chloride  prepared 
from  bile.  On  evaporation  the  watery  solution  gives 
the  same  crystals  down  to  the  last  drop.  It  contains 
31*68%  of  platinum,  pointing  to  the  formula  2  (C5H14 
NO  01)  Pt014,  which  is  the  same  as  that  of  the  com- 
pound from  bile. 

7.  To  establish  the  presence  of  glycerophosphoric 
acid,  the  residue  insoluble  in  alcohol  is  redissolved  in 
water,  freed  from  baryum  by  sulphuric  acid,  saturated 
with    calcium    carbonate,   the    sulphuric  acid  exactly 
precipitated   by    baryum    chloride,    and    the    filtrate 
evaporated    down ;    the  crystalline    calcium    glycero- 
phosphate  which  separates,  after  washing  with  alcohol 
and  drying  at  100°,  gives  results  corresponding  with 
the  formula  C3H7CaP06. 

8.  The  baryum  salt,  insoluble  in  water,  is  decom- 
posed by  boiling  with  hydrochloric  acid,  when  a  fluid 
stratum,  nearly  solid  on  cooling,  separates,  and  may 
be  washed  with  water.      The   liquid  contains  much 
baryum  chloride,   also  glycerophosphoric  acid,  partly 
decomposed  into  phosphoric  acid  and  glycerine  during 
the  boiling. 

9.  The  fatty   acids   dissolve   in  ammonia    and  are 
precipitated  as  lead  salts  by  lead  acetate.     From  the 


142  LEUOIO   ACID. 

precipitate  ether  extracts  a  considerable  quantity  of 
lead  oleate.  The  oleic  acid  is  purified  by  crystallising 
the  baryum  salt  from  boiling  alcohol ;  and  decom- 
posing the  pure  salt  by  hydrochloric  acid. 

10.  The  lead  salts,  insoluble  in  ether,  are  decomposed 
with  hydrochloric  acid  and  the  free  acids  crystallised 
from   alcohol.      They   are    finally   obtained    in  white 
glistening  plates,  melting  at  56*7°  C.,  corresponding  in 
composition  with  margaric  acid,   but  containing  pro- 
bably a  little  stearic,  though  Heintz's  process  of  frac- 
tional precipitation  with  magnesium   acetate  fails  to 
effect  a  separation. 

11.  Add  alcoholic  potash  to  an  ether-alcohol  solu- 
tion of  lecithine,   and  observe  the  precipitation  of  a 
crystalline  potassium  salt.     Hence  lecithine,  like  glyko- 
koll,  is  at  once  acid  and  base  ;  it  is  also,  moreover,  a 
fat. 


Leucic  acid,  C6H1303. —  1.  Pass  nitrous  acid 
through  a  warm  aqueous  solution  of  leucine,  add  a 
small  quantity  of  leucine,  evaporate  to  a  syrup.  Ex- 
tract the  syrupy  residue  with  ether.  Evaporate  the 
ethereal  solution,  when  the  leucic  acid  will  crystallise 
out.  Press  the  crystals  between  blotting  paper,  when 
nearly  pure  leucic  acid  is  obtained. 

2.  Leucic  acid  is  soluble  in  water,  alcohol,  and 
ether.  It  crystallises  in  colourless  needles.  Heat  a 
portion  of  leucic  acid  on  a  watch  glass  placed  on  a 
water  bath ;  the  acid  will  melt  and  volatilise,  the  sides 
of  the  glass  becoming  fringed  with  crystals  of  the 
sublimed  acid. 


LEUCINE.  143 

3.  Add  to  a  solution  of  leucic  acid  a  solution  of 
copper  acetate  ;  green  flocks  of  copper  leucate  will  be 
precipitated,  sparingly  soluble  in  'water,  easily  soluble 
in  boiling  alcohol; 

4.  Add  to  a  concentrated  solution  of  leucic  acid  a 
solution  of  lead  acetate ;  a  white  flaky  precipitate  of 
lead  leucate  falls.     Boil :  part  of  the  precipitate  dis- 
solves,   the    rest    melts    into    a    white    mass,    which 
becomes  hard  and  brittle  on  cooling. 

Leucine,  C6H13N02. — 1.  Boil  one  part  of  cowhorn 
shavings  with  four  parts  of  concentrated  sulphuric 
acid  and  twelve  parts  of  water  for  six  hours,  re- 
newing the  water  as  it  evaporates.  Add  an  excess 
of  milk  of  lime,  boil  for  some  hours,  strain,  and 
press.  Mix  the  nitrate  with  a  very  slight  excess  of 
sulphuric  acid,  and  evaporate  the  nitrate.  Spherical 
crystalline  tufts  of  tyrosine  will  be  first  deposited. 
Separate  these,  and  continue  the  evaporation,  when 
leucine  will  be  deposited,  in  scales. 

2.  Collect  these    scaly  masses  of    impure  leucine, 
press  them  between  filter  paper.     Triturate  them  in  a 
mortar  with   slightly  warm    concentrated   nitric   acid 
until  dissolved ;  dilute  the  solution  with  water,  and  add 
to  it  solution  of  mercuric  nitrate  as  long  as  a  precipi- 
tate falls ;  filter,  treat  filtrate  with  sulphuretted  hy- 
drogen ;    filter,  neutralise  the  filtrate  with   ammonia, 
and  evaporate  till  the  leucine  begins  to  crystallise  out ; 
allow  to  cool,  when  nearly  pure  leucine  will  be  depo- 
sited. 

3.  To   obtain  it  perfectly  pure  dissolve  in  boiling 


144  LEUCINE. 

water,  treat  with  pure  and  good  animal  charcoal,  filter, 
and  evaporate  filtrate  till  a  pellicle  begins  to  form, 
then  pour  the  boiling  hot  solution  into  three  or  four 
times  its  volume  of  absolute  alcohol.  Allow  to  stand, 
collect  on  a  filter,  and  press  between  filter  paper; 
perfectly  white  leucine  is  thus  obtained. 

4.  Leucine  is  sparingly  soluble  in  cold,  but  mode- 
rately soluble  in  hot  water,  almost  insoluble  in  alcohol ; 
it  dissolves  in  acids  and  alkalies. 

5.  Heat  gently  a  portion  of  leucine  in  a  wide  test 
tube,  it  will  sublime  in  snow-white  flocks.     Heat  some 
leucine  on  a  piece  of  platinum,  it  will  take  fire  and 
burn  with  a  white  flame. 

6.  Heat   some   leucine   mixed   with   soda  lime ;    a 
strong  smell  of  ammonia  is  evolved,  proving  the  pre- 
sence of  nitrogen. 

7.  Dissolve  leucine  in  water,  pass  nitrous  acid  gas ; 
leucic  acid  is  formed. 

8.  Add  to  a  solution  of  leucine  a  concentrated  solu- 
tion of  sulphate  of  copper  gradually  until  an  excess  of 
copper  is  present ;   the  fluid  takes  a  deep  blue  colour. 
Treat  the  deep  blue  solution  with  an  excess  of  baryum 
carbonate,  and  filter ;  on  evaporation  the  compound  of 
copper   and     leucine   is   deposited   in   blue   crystalline 
granules. 

Luteine. — I.  From  corpora  luted  of  Mammals. 

1.  Dissect  out  the  corpora  lutea  from  the  ovaries 
(of  cows),  pound  the  corpora,  warm,  and  press 
out  the  juice. 


LUTEINE. 


145 


2.  Reactions  of  the  juice. 

a.  Add  nitric  acid ;  a  precipitate,  pink  at  first, 
afterwards  greenish-yellow,  appears. 

b.  Add  sulphuric   acid;    a  precipitate  will  be 
formed,  which  will  redissolve  and  turn  red- 
dish-brown. 

c.  Add  sulphuric    acid  and   a    little  sugar;    a 
fine  purple  colour  will  be  produced,  showing 
in  the  spectroscope  one  band  in  green. 


A  aBC 


Eb 


HH' 


spectrum  of  juice  of  corpora  lutea  treated  with  sulphuric  acid. 

d  Add  hydrochloric  acid ;  no  reaction. 
3.  Reactions  of  Alcoholic  Extract. 

a.  Dry  the  solid  residue  of  the  corpora,  extract  two 
or  three  times  with  boiling  alcohol  of  85%,  filter 
hot,  allow  the  mixed  extracts  to  stand  in  the 
dark  till  clear,  decant  the  liquid,  and  examine 
as  follows  : 

b.  Add  water;    a  turbidity  will  be  produced, 
not  removable  by  heating. 

c.  Add  potash  solution ;   a  yellow  precipitate 
will  gradually  deposit. 

d.  Add  mercuric  chloride,  auric  chloride,  or  pla- 
tinic  chloride  ;    no  reduction  will  take  place. 

e.  Add  mercuric  nitrate  ;  a  copious  yellow  pre- 
cipitate will  fall,  becoming  white  on  heating. 

10 


146 


LUTEINE. 


/.  Add  mercuric  acetate ;  a  yellow  precipitate 

will  fall,  leaving  the  liquid  colourless. 
g.  Add  copper  acetate  ;  green  precipitate. 
h.  Add  lead  or  zinc  acetate  ;  on  standing  all  the 

yellow  matter  will  go  down  as  an  oily  layer. 

Examine  with  spectroscope  with  lime  light. 

Two  bands  in  blue  and  a  third  feeble  one  in 

violet  will  appear. 


^. 


AaBC 


Eb 


HH' 


Spectrum  of  ovario-luteine  in  alcohol. 

4.  Set  aside  the    alcohol  solution   to    evaporate 
spontaneously.     The  fatty  residue  will  gradu- 
ally deposit  orange-red  crystals  of  ovario-luteine. 
Shake  the  mixture  with  absolute  alcohol  till  the 
fat  is  removed,  then  with  repeated  small  quan- 
tities of  ether.     Lastly,  wash  with  ether,  press 
between  paper,  and  dry. 

5.  Reactions  of  ovario-luteine  crystals. 

a.  The   crystals  are  soluble  with  a  yellow  or 
orange  colour  in  hot  alcohol,   ether  chloro- 


AaBO 


Eb 


HH' 


Spectrum  of  ether  solution  of  corpus  luteum. 


LUTEINE. 


147 


form,    carbon    disulphide,    and    hot    glacial 
acetic  acid. 

b.  To  a  small  quantity  of  the  crystals  add  nitric 
acid ;  a  blue  colour,  turning  rapidly  yellow, 
is  produced.     The  acetic  acid  solution  gives 
the  same  reaction. 
6.  Reactions  of  Chloroform  /Solution. 

a.  Dry  the  solid  residue  of  the  corpora  lutea, 
and  extract  with  chloroform.     Test  the  solu- 
tion as  follows : 

b.  Examine  with  spectroscope  with  lime  light. 
Two  bands  in  blue  will  be  shown. 


AaBO 


D 


Eb 


HH' 


Spectrum  of  chloroform  solution  of  corpora  lutea. 

c.  Add  nitric  acid ;    the  solution  will  become 
colourless. 

d.  Evaporate  the  solution  in  a  current  of  air. 
A   peculiar    odour  will   be    noticed,   and   a 
yellow    residue   left.      To   the   residue    add 
sulphuric   acid ;    a   dirty  green    colour    will 
appear.       Add    a   little    sugar;    no    purple 
colour  will  ensue. 

II.  Ovo-luteine,  or  luteine  from  egg-yelks. 

1.    Alcohol  extract. — Boil  the  yelk  with  85%  al- 
cohol, filter,  and  allow  to  stand  till  clear.     It 


148  LUTEINE. 

will  show  the  same  three  bands  as  the  ether 
solution,  but  diminished  in  intensity  by  heat, 
and  recovering  the  same  appearance  when  cold. 


AaBC 


Spectrum  of  egg  luteine  in  alcohol,  cold. 
AaBC         D  EbF  G  HH' 


Spectrum,  of  egg  luteine  in  alcohol,  hot. 

2.  Ether  extract. — Prepared  similarly;  the  ether 
extract  shows  three  bands  ,in  a  slightly  different 
position. 


AaBC 


Spectrum  of  egg  luteine  in  ether. 

3.  Chloroform  extract. — Digest  egg-yelk  in  chloro- 
form, filter,  and  allow  to  stand  till  clear.  The 
solution  has  a  fine  yellow  colour,  and  in  the 
spectroscope  shows  three  bands. 


149 


AaBC         D 


HH' 


Spectrum  of  egg  luteine  in  chloroform. 

III.  Butyro-luteine. 

1.  Butter  is  digested  with  chloroform  and  filtered, 
Three  bands. 


AaBC         D 


Eb 


HH' 


Spectrum  of  butyro-luteine  in  chloroform. 

2.  Dried  by  heat  and  filtered  hot.  Three  bands, 
fainter  when  heated;  third  only  visible  when 
just  cooling. 


AaBC 


Eb 


HH' 


Spectrum  of  butyro-luteine  in  fused  butter. 

IV.  Cysto -luteine. 

1.  The  yellow  fluid  contained  in  an  ovarian  cyst 
is  examined  before  the  spectroscope  with  the 
lime  light.  Three  bands  in  blue  will  be  ob- 


150 


LUTEINE. 


served  in  the    same  position  as   those  of  the 
chloroform  solution  of  ovario-luteine. 


AaBC 


HH' 


Spectrum  of  cysto-luteine. 

V.  Sero-luteine. 

1.  Allow  blood  to  stand,  and  decant  the  serum. 
Set  aside  the  latter  to  deposit,  pour  off  the 
liquid,  and  filter  it  through  paper  repeatedly 
till  clear.  Before  the  spectroscope  it  will  show 


AaBC 


Eb 


Spectrum  of  sero-luteine. 

the  bands  of  hematocrystalline  (q.  v.\  and  also 
(probably)  one  band  and  a  doubtful  second, 
corresponding  to  the  ovario-luteine  bands.  If 
diluted  till  the  blood  bands  disappear  the 
luteine  bands  will  also  become  invisible. 


VI.  Intestino-luteine,  from  Infants. 

1.  Mix  the  yellow  faeces  of  sucking  infants  with 
alcohol    in    excess,    filter   from   the    flakes   of 


LYMPH. 


151 


caseine,  and  examine  the  solution  with  the  spec- 
troscope. One  band  and  a  doubtful  second  in 
the  positions  of  the  other  luteine  bands,  will  be 
perceived. 


A  aBC         D 


HH' 


Spectrum  of  intestine -luteine. 

The  solution  will  deposit  crystals  of  chole- 
sterine.  Examine  also  the  ether  and  chloroform 
solutions. 

Compare  with  the  above  a  chloroform  extract 
of  dried  faeces  of  adults.  It  will  give  no  band. 

Lymph. — 1.  Examine  under  the  microscope;  white 
corpuscles  and  fat  globules  will  be  noticed. 

2.  Allow  fresh  drawn   lymph  from  a  blister,   or  a 
fistula  of  a  lymph  vessel  to  stand ;  it  will  coagulate. 
Kemove   the  coagulated   threads   by  beating   with   a 
bundle  of  twigs,  and  wash  them   with  water.     They 
will  be  found  to  consist  offibrine  (see  Fibrine). 

3.  Strain  the  liquid  and  heat  it  to  boiling.     A  pre- 
cipitate of  albumen  in  flakes  will  be  produced. 

4.  Filter ;  to  the  hot  filtrate  add  a  slight  excess  of 
dilute  sulphuric  acid;    allow  to  cool,  and   shake  re- 
peatedly with  small  portions  of  ether.     Evaporate  the 
ether  to  dryness,  and  digest  with  water.     The  part 


152  MILK. 

insoluble  in  water  will  consist  of  fats.     The  soluble 
portion  will  contain  lactic  acid  (q.  v.). 

5.  Dry  a  portion  of  fresh  lymph  at  100°  C.,  powder 
the  residue,  and  burn  to  a  white  ash.  Examine  the 
ash :  it  will  contain  sulphate,  phosphate,  carbonate, 
&c.,  of  the  alkalies,  and  a  small  quantity  of  earthy 
salts.  Notice  prevalence  of  soda  over  potash  salt. 

Melanine. — The  black  pigment  of  the  eye  or  of  mela- 
notic  cancers  must  be  isolated  as  much  as  possible, 
and  purified  by  solution  in  ammonia  and  precipitation 
by  hydrochloric  acid.  It  will  possess  a  composition 
similar  to  uromelanine  (q.  v.)9  but  different  properties. 
A  portion  will  be  found  to  be  quite  insoluble  in  any 
ordinary  reagent. 

Milk. — 1.  Milk  has  a  specific  gravity  1*018  to 
1-045. 

2.  Test  the  reaction  with  litmus  paper ;  the  reaction 
is  usually  alkaline. 

3.  Examine  some  milk  under  the  microscope ;  it  will 
appear   as    a    clear   liquid,    in   which   float   the   milk 
globules.     These  vary  in  diameter  from  about  0'0012 
to  0-0030  inch. 

4.  Add  a  little  acetic  acid  to  milk  ;  the  globules  will 
become  distorted. 

5.  Shake  up  some  milk  with  ether;  the  globules; 
though  they  consist  of  fat,  are  not  dissolved.     This  is 
due  to  the  fact  that  each    globule   has  an  envelope 
which  is  insoluble  in  ether. 

6.  Shake  up  some  milk  with  caustic  potash,  which 


MILK.  153 

dissolves  the  envelope.     On  now  treating  with  ether 
the  globules  will  be  dissolved. 

7.  The  colostrum  (milk  secreted  during  the  first  two 
or  three  days  after  parturition)  is  characterised  by  the 
presence    of   granular   bodies.      Examine   under   the 
microscope  :  the  granular  bodies  will  be  seen  to  be 
composed  of  irregular  aggregations  of  small  fat  glo- 
bules, and  united  by  an  albuminous  amorphous  granu- 
lar substance.     Treat  with  iodine  water ;  the  albumen 
will  be  dyed  yellow.'     Potash  and  acetic  acid  break  up 
these  granular  bodies. 

8.  Evaporate  20  cc.  of  milk  to  dryness  in  a  small 
weighed  porcelain  or  platinum  crucible  on  the  water- 
bath.     Dry  in  an  air-bath  for  several  hours  at  110°  C. 
and  weigh ;  the  increase  in  the  weight  of  the  crucible 
gives  the  solid  residue  in  the  milk. 

9.  Ignite  the  dried  residue  over  a  Bunsen  or  Argand 
burner;    allow  to  cool   and   weigh.      The  difference 
between  this  weight   and  the  original  weight  of  the 
crucible  gives  the  ash  of  the  milk. 

Milk  contains  about  10%  solid  residue,  and  0*1  to 
0-5%  of  ash. 

10.  Evaporate  50  cc.  of  milk  on  a  water-bath  almost 
to  dryness  in  a  weighed  porcelain  dish;  add  acetic 
acid.     Exhaust  the  residue  successively  with   ether, 
alcohol,  and  water.     Dry  the  exhausted  residue  and 
weigh ;  the  increase  in  the  weight  of  the  dish  gives  the 
caseine  in  the  milk. 

11.  Evaporate  the  ethereal  extract  to  dryness  in  a 
weighed  crucible  and  weigh ;  the  increase  of  weight 
will  give  the  quantity  of  fat. 


154  MUOINE. 

12.  Add  to  100  cc.  of  milk  solution  of  calcium 
chloride ;  the  caseine  is  precipitated ;  filter ;  add 
potash  solution  to  precipitate  excess  of  calcium,  and 
estimate  the  sugar  present  in  the  filtrate  with  standard 
solution  of  potassio-tartrate  of  copper. 
Milk  contains  2  to  4%  caseine. 

1-5  to  4%  fat. 
„  4  to  5%  sugar  (lactose). 

Mucine. — 1.  Dilute  mucus  with  four  vols.  of  water 
and  filter.  Digest  the  insoluble  matter  (mucine)  with 
a  weak  solution  of  potash,  filter,  neutralise  with  acetic 
acid,  wash  the  precipitate  with  water,  alcohol,  and 
ether,  and  use  it  for  the  following  reactions. 

2.  Dry  a  portion  and  burn  on   platinum  foil.      A 
white  alkaline  ash  containing  calcium  phosphate  will 
remain. 

3.  Fuse  with  caustic  potash,  dissolve  in  water,  and 
add  a  drop   of  lead   acetate.     No   black   precipitate, 
showing  the  absence  of  sulphur. 

4.  Mix  with  cold  water  and  boil.     It  will  gradually 
dissolve.    Add  alcohol;  the  mucine  will  be  precipitated 
in  flakes. 

5.  Dissolve  mucine  in  a  dilute  acid  or  alkali,  and 
add  potassium  f err o cyanide.     No  precipitate. 

6.  Dissolve  in  glacial   acetic   acid  and  boil.      Add 
potassium  ferrocyanide ;  white  precipitate. 

7.  Heat  with  concentrated  nitric  acid :  the  mucine 
will  turn  yellow  and  dissolve. 

8.  Dissolve  in  very  weak  caustic  potash,  and  add 
basic  lead  acetate  or  tannic  acid ;  white  precipitate. 


MUSCLES.  155 

9.  Dissolve   in  dilute   hydrochloric   acid,   and   add 
mercuric  chloride ;  only  a  slight  turbidity  will  ensue. 


Muscles. — Striated  voluntary  and  involuntary  muscles. 
— 1.  Examine  under  microscope.     They  will  be  found 
to  consist  of  fibres  bound   together  in  bundles,   and 
marked  with  transverse  striae. 

•  2.  Free  the  muscles  of  a  recently-killed  animal  from 
blood  by  injecting  through  the  vessels  a  one  per  cent, 
solution  of  sodium  chloride.  They  must  then  be 
frozen,  minced,  mixed  with  four  vols.  of  snow  con- 
taining a  little  sodium  chloride.  The  mass  will  liquefy, 
and  must  be  quickly  filtered  at  0°C.  The  nearly  clear 
filtrate  on  regaining  the  ordinary  temperature  will 
coagulate.  Stir  with  a  rod,  and  separate  the  coagulum 
from  the  serum. 

3.  Wash   the   coagulum   with   water,   alcohol,   and 
ether.     It  will  be  found  to  consist  of  myosine  (q.  v.). 

4.  Heat  the  serum  to  boiling  :  albumen  will  precipi- 
tate in  flakes. 

5.  Extract  the  cake  which  remains  after  the  extrac- 
tion of  myosine  and  albumen  by  process  2  with  pure 
water,   and   observe   that   the   red    colouring   matter 
myochrome,  identical  with  hemato-crystalline,  dissolves. 
Study    its     properties     as     prescribed     for    hemato- 
crystalline. 

6.  Expose  a  piece  of  fresh  muscle  to  oxygen  under 
a  receiver,  and  observe  that  oxygen  is  absorbed  and 
carbonic  acid  evolved. 

7.  After  extraction  of  the  myochrome  (5),  treat  the 


156  MYELINE. 

residue    with    dilute    hydrochloric    acid    and    obtain 
syntonine  (q-v.). 

8.  Extract  Jcreatine,  Jcreatinine,  and  inosic  acid  by  the 
processes  described  under  those  bodies. 

9.  Extract  sarJcine  and  xanthine  by  the  processes 
described  under  those  bodies. 

10.  Extract  inosite   and   dextrine  by  the   processes 
described  under  those  bodies. 

11.  Extract  Jcreatylic  acid  by  a  process  similar  to 
that   prescribed   for   the   extraction    of  kryptophanic 
acid  from  urine. 

12.  Burn  a  portion  of  muscle  freed  from  blood  as 
above.     Examine   the  ash,  and   observe   that  potash 
salts  prevail  in  it. 

13.  Examine  mercantile  extract  of  meat  (Liebig's) ; 
observe  what  quantity  of  it  is  soluble  in  alcohol  of 
80%  strength.     Burn  a  quantity,  and  observe  that  it 
leaves  about  18%  of  ash,  of  which  half  is  potash. 

14.  Examine  brine  in  which  meat  has  been  kept; 
observe  that  it  contains  much  albumen,  but  no  red 
colouring  matter. 

15.  Treat  red  salted  meat,  such  as  ham,  with  water, 
and  observe  that  the  hemato-crystalline  is  insoluble  in 
it.     Boil  with  alcohol:    the  red  matter  will  dissolve, 
and   the    solution   will    show   a   particular   spectrum, 
differing  from  the  spectra  of  hemato-crystalline,  hema- 
tine,  or  cruentine. 

Myeline. — Extract  brain  or  blood -corpuscles  by 
ether,  and  evaporate  the  extract.  The  matter  thus 
obtained  has  received  the  name  of  "  my  dine"  It  is  a 


NEKVE.  157 

mixture  of  cerebric  acid,  several  lecithines,  cholesterine, 
and  fats.  It  is  interesting  as  a  microscopic  object 
from  its  developing  peculiar  stringy  growths  when 
placed  in  water. 

Myosine. — From  the  muscles  of  an  animal  just 
killed;  the  plasma  or  liquid  portion  is  removed  by 
pressure,  beaten  with  a  rod  while  it  coagulates,  and 
the  coagulated  flakes  of  myosine  washed  with  water. 
In  properties  myosine  closely  resembles  fibrine,  but  is 
flaky,  not  fibrous,  more  transparent  in  appearance, 
easily  soluble  in  a  10%  solution  of  sodium  chloride,  and 
precipitated  on  dropping  this  solution  into  water. 

Nerve. — 1.  Nerve  is  similar  to  brain  in  constitution. 
The  brain  fats  which  have  been  found  in  nearly  all 
parts  of  the  organism  are  probably  due  to  the  presence 
of  minute  ramifications  of  nerves. 

2.  Examine   under   microscope.      Nerves     consist 
of  either  fibres  or  cells.     The  fibres  are  generally  made 
up  of  an  outer  sheath,  a  "medullary  substance,"  con- 
taining albuminous  matter    and   fats,    and   a  central 
"  axis    cylinder"  of  albuminous  matter  alone.      The 
medullary  substance,  and  perhaps  the  axis,  coagulate 
after  death.     The  nerve- cell  or  vesicle  has  a  nucleus 
and  nucleolus,  and  differs    in  composition  from   the 
nerve-fibre,  being  soluble  in  acetic  acid. 

3.  The    substance    forming    the    "  axis    cylinder" 
resembles  fibrine  and  myosine,  but  differs  from  the 
former  by  being  insoluble  in  potassium  nitrate,  from 
the  latter  by  not  dissolving  in  dilute  acids. 


158  OLEOPHOSPHORIC   ACID. 

4.  The  nerve-cells  contain  a  substance  resembling 
caseine. 

5.  The    "  sheath"    of  the   nerve-fibres   appears   to 
consist  of  elastic  tissue  (q.  v.). 

(See  Brain  and  Oleophosphoric  Acid.) 

Oleophosphoric  Acid  (Fremy). — 1.  The  ethereal  ex- 
tract obtained  in  the  preparation  of  cerebrine  (q.  v.)  is 
evaporated  and  digested  with  a  small  quantity  of  ether. 
The  solution  must  be  shaken  with  dilute  sulphuric  acid 
to  remove  soda,  then  washed  with  water  to  remove 
excess  of  acid.  Distil  off  the  ether,  and  dissolve  the 
residue  in  boiling  alcohol;  on  cooling  the  oleophos- 
phoric  acid  will  be  deposited,  and  must  be  freed,  as  far 
as  possible,  from  oleine  by  washing  with  cold  absolute 
alcohol,  and  from  cholesterine  by  ether,  in  which  the 
latter  is  the  more  soluble. 

2.  Sodium  oleophosphate  may  also  be  obtained  from 
muscle,   &c.,  by  extracting  with  cold  dilute  alcohol, 
and  treating  the  extract  as  above. 

3.  Oleophosphoric  acid  is  a  yellowish  viscous  sub- 
stance, soluble  in  ether  and  in  hot  alcohol,  insoluble  in 
cold  absolute  alcohol  and  in  water,  but  swelling  up 
slightly  in  boiling  water  from  the  presence  of  a  little 
cerebric  acid. 

4.  Long  boiling  with  water  or  alcohol,  especially  if 
acidified,  decomposes  it  into  oleine  and  phosphoric  acid, 
or  into  oleic  and  glycerophosphoric  acids.     The  same 
change  takes    place  in   the    brain    by  physiolysis    or 
putrefaction. 


OMICHOLIC   ACID.  159 

5.  Alkalies  in  excess  resolve  it  into  phosphate,  oleate, 
and  glycerine. 

6.  Heated  on  platinum  foil  it  blackens,  burns,  and 
leaves    a   charcoal    containing  phosphoric  acid  corre- 
sponding to  2%  of  phosphorus  in  the  original  substance. 
The  phosphorus  may  also  be   determined  by  decom- 
posing the  compound  by  fuming  nitric  acid,  when  the 
phosphoric  acid  is  found  in  the  aqueous  layer. 

7.  Oleophosphoric  acid  differs  from  oleine  in  being 
insoluble  in  cold  absolute  alcohol.     It  has  not  yet  been 
obtained  pure,  nor  can  it  be  produced  artificially,  but  a 
similar  compound  of  sulphuric  acid  and  oleine  is  known. 

Omicholic  Acid,  015H32N04  (See  Uromelanine) . — 1. 
Boil  Urochrome  (q.  v.)  with  dilute  sulphuric  acid  until 
the  fluid  assumes  a  dark  red  colour  ;  add  water,  reddish 
brown  flakes  are  precipitated,  collect  those  flakes  and 
extract  with  boiling  alcohol ;  filter  the  solution  when 
cool,  and  concentrate  the  filtrate  and  pour  into  cold 
water  ;  a  red  powder  is  deposited ;  collect  this  powder 
and  extract  with  ether,  and  filter. 

2.  Allow  the  ethereal  solution  to  evaporate  sponta- 
neously;  the  Omicholic  acid  is  left  as  a  resinous  syrup 
mixed  with  Omicholine. 

3.  Treat  with  ammonia;  the  omicholic  acid  is  dis- 
solved whilst  the  omicholine  remains. 

4.  Examine  the  ethereal  solution  of  omicholic  acid 
with  the  spectroscope.     It  has  a  spectrum  showing  an 
absorption  band  in  the  green.     The  ammonia  solution 
has  no  band. 


160 

AaBC         D 


OMICHOLINE. 
Eb        F  G 


HH' 


Spectrum  of  omicholic  acid. 

5.  Heat  a  very  small  portion  on  platinum  foil ;    a 
very  strong  urinous  odour  will  be  evolved. 

6.  Examine  the  ethereal  or  chloroform  solution  in 
concentrated   sunlight,    and    notice   a    strong   green 
fluorescence. 

Omicholine,  C33H38N05  (see  Uromelanine). — 1.  The 
alcohol  solution  of  resins  obtained  as  described  under 
Uromelanine  must  be  concentrated  and  poured  into 
water.  Dry  the  precipitate,  extract  with  ether,  and 
filter.  The  portion  insoluble  in  ether  is  Uropittine 
(q.  v.). 

2.  Evaporate  the  ether,  dissolve  the  residue  in  a 
little  hot  absolute  alcohol,  and  pour  into  water.  Col- 
lect the  flocculent  precipitate  and  treat  with  dilute 
ammonia.  Omicholic  acid  will  dissolve,  while  Omicholine 
will  remain  insoluble. 


AaBC         D 


Spectrum  of  omicholine. 


PEPSINE.  161 

3.  Omicholine  is  insoluble  in  cold,  slightly  soluble  in 
boiling  water,  insoluble  in  alkalies  when  pure,    very 
soluble  in  alcohol  or  ether  with  a  red  colour. 

4.  Heat  a  small  portion  on  platinum  foil ;  a  power- 
ful urinous  odour  will  be  evolved. 

5.  Examine  the  alcohol  solution  with  the  spectro- 
scope ;  a  band  in  green  will  be  observed. 

6.  Examine   with  a  lens    in  sunlight ;  the   solution 
fluoresces  green. 

Pancreatic  Juice. — 1.  Notice  appearance  and  alka- 
line reaction. 

2.  Add  tannic  or  a  mineral  acid  ;  a  white  precipitate 
will  be  produced. 

3.  Heat  to  72°,  a  white  precipitate  will  also  appear. 

4.  Add  three  or  four  volumes  of  94%  alcohol,  filter, 
dry   the    precipitate,     dissolve   in    water,    and    filter. 
Digest  solution  with  some  starch ;  the  latter  will  be 
dissolved    and    converted    into    dextrine    and    sugar. 
Digest    with    coagulated    albumen ;    it    will  dissolve. 
With  fats  it  will  form  an  emulsion. 

5.  Evaporate  the  juice  to  a  low  bulk  and  exhaust 
with  ether."    The  ethereal  solution  must  be  examined 
for  fats.      The  aqueous    portion  must  be   tested  for 
leucine  and  tyrosine  (q.  v.). 

6.  Treat  pancreatic  juice  with  a  little  chlorine  water ; 
a  reddish  colour  will  be  produced. 

7.  Evaporate,  burn,  and  analyse  ash. 

Pepsine. — 1.  Treat  the  glandular  layer  of  a  stomach 
with  dilute  tribasic  phosphoric  acid;  filter  and  neutralise 

11 


162  PROTAGON. 

the  filtrate  with  lime-water.  Collect  the  precipitate  on 
a  filter,  wash  and  treat  with  dilute  hydrochloric  acid. 
Treat  the  clear  solution  with  lime-water,  collect  the 
precipitate,  dissolve  in  dilute  hydrochloric  acid,  and  add, 
through  a  thistle  funnel  reaching  to  the  bottom  of  the 
solution  a  saturated  solution  of  cholesterine  in  a  mix- 
ture of  one  part  ether  and  four  alcohol,  and  shake  the 
whole  well.  Filter  off  the  precipitate  which  consists 
of  cholesterine  and  pepsine,  wash,  and  finally  shake  up 
in  a  bottle  with  ether;  allow  to  stand,  remove  the 
ethereal  solution  of  cholesterine  with  a  syphon  and 
filter  the  remaining  liquid.  The  filtrate  will  consist  of 
a  solution  of  pepsine. 

2.  Acidify  this  solution  feebly  with  hydrochloric  acid, 
add  to  the  solution  thus  acidified  some  albumen ;  it 
will  rapidly  be  dissolved. 

3.  Add  to  the  solution  tannic  or  mercuric  chloride ; 
no  precipitate  is  formed. 

Protagon  (Liebreich). — 1.  The  brain  of  an  animal 
just  killed  is  freed  from  blood  by  injecting  water  till  it 
issues  colourless.  The  substance  is  then  comminuted, 
shaken  with  repeated  quantities  of  water  and  ether  (to 
remove  cholesterine  and  matters  soluble  in  water),  and 
the  residue  digested  with  warm  (45°  C.)  85%  alcohol. 
The  alcoholic  extract  on  cooling  deposits  a  flaky 
precipitate,  which  must  be  exhausted  with  cold  ether, 
and  purified  by  recrystallising  from  warm  alcohol. 
Pure  protagon  has  the  following  properties. 

2.  Light  flocculent  powder,  consisting  under  the 
microscope  of  radiated  needles,  little  soluble  in  cold, 


PTYALINE.  163 

more  soluble  in  hot,  alcohol  and  ether.  In  water  it 
swells  up  to  an  opalescent  solution,  which  is  coagu- 
lated by  the  addition  of  salts.  From  the  coagulated 
flakes  the  salts  are  almost  entirely  removed  by  washing 
with  water,  leaving  the  protagon  unchanged. 

3.  In  warm  glacial  acetic  acid  it  dissolves  to  a  clear 
solution,     which    deposits    crystalline    protagon    on 
cooling. 

4.  It  softens  at  a  temperature  of  75°  to  80°,  and 
decomposes  below  100°.      When  burned    it  leaves   a 
dense  charcoal  difficult  of  combustion  and  containing 
phosphoric  acid. 

5.  By  the  action  of  alkalies  or  boiling  dilute  HC1  it 
yields   cerebrine   and  the   decomposition    products  of 
lecithins  (q.v.).     (See  Cerebric  Acid.) 

Pty aline. — 1.  Treat  a  quantity  of  saliva  first  with 
dilute  phosphoric  acid  and  then  with  lime  water. 
Decant  the  clear  liquid  ;  shake  up  the  precipitate  with 
distilled  water  and  filter.  The  filtrate  is  a  solution  of 
the  active  ferment  ptyaline,  which  can  be  precipitated 
by  the  addition  of  alcohol. 

2.  Treat    some   starch   with  the    above-mentioned 
aqueous    solution   at   a   temperature   of  35°;    it   will 
dissolve  and  be  finally  converted  into  dextrine  and  sugar. 

3.  The  active  properties  of  ptyaline  are  destroyed  by 
a  temperature  above   60°   0.,   or  by  strong  acids  or 
alkalies. 

4.  Treat  a  little  solid  ptyaline  with  nitric  acid.     No 
yellow  colour  will  be  produced,  showing  that  it  is  not 
an  albuminoid. 


164  PUS. 

5.  Heat  with  soda  lime  in  a  tube :  ammonia  will  be 
evolved,  showing  presence  of  nitrogen. 

6.  Fuse  with  caustic  potash,  dissolve  in  water  and 
add  a  drop  of  lead  acetate.     A  black  precipitate  will 
form,  showing  presence  of  sulphur. 

Pus. — 1.  Examine  under^ microscope  :  pus  corpuscles, 
identical  with  the  white  corpuscles  of  the  blood,  will 
be  noticed.  Observe  appearance  and  reaction  with 
litmus  paper. 

2.  Exhaust  the  pus  with  twice  its  volume  of  boiling 
90%    alcohol,    containing   a   little   hydrochloric   acid, 
evaporate  to  one  third,  mix  with  three  or  four  times 
its  bulk  of  ether,  shake  well,  and  decant  or  fill  the 
liquid.     Examine  the  solution  and  the  insoluble  residue 
by  the  methods  described  under  fats ;   cerebric,  oleic, 
and  palmitic  acids  and  cholesterine  will  be  found. 

3.  Dilute  pus  with  three  volumes  of  water  containing 
a  little  sodium  chloride,  and  by  nitration  and  decanta- 
tion  separate  the  corpuscles  from  the  serum. 

4.  Heat  the  serum :  a  precipitate  of  albumen  will  be 
formed.     Filter  :  test  a  portion  of  the  nitrate  for  sugar 
by  the  copper  test.     Evaporate  another  portion  to  a 
low  bulk  and  add  nitric  acid  ;  a  crystalline  precipitate 
of  urea  nitrate  will  indicate  urea.      In  another  portion 
test  for  leucine  (q-v.). 

5.  Digest  the    corpuscles   with  a   10%   solution  of 
sodium  chloride,  filter  or  decant,  and  mix  the  solution 
with  a    large    quantity    of   distilled  water.      A  flaky 
precipitate  will  form  of  a  substance  allied  to  myosine. 
The  portion    of   the    corpuscles    insoluble  in  sodium 


TYOCYANINE.  165 

chloride  must  be  digested  with  dilute  hydrochloric  acid, 
filtered,  and  the  filtrate  carefully  neutralised  Yvdth 
soda.  A  precipitate  of  pyine  will  appear  (q.v.). 

6.  Distil  fresh  pus  carefully  with  dilute  phosphoric 
acid.      To  the  distillate  add  some  sodium  carbonate  to 
very  slight  alkaline  reaction,  evaporate  down  and  test 
for  volatile  acids  (q.v.). 

7.  Evaporate  pus  to  dryness  at  100°  C.  and  burn. 
Examine  the  ask. 

Pyine.  —  1.  Obtain  from  pus  by  the  method 
described  under  Pus,  5. 

2.  Dissolve  in  dilute  caustic  potash,  and  add  acetic 
acid  :  a  precipitate  will  appear,  insoluble  in  excess  of  the 
acid. 

3.  To  the  solution  in  potash  add  hydrochloric  acid: 
a  precipitate  soluble  in  excess  will  be  produced. 

4.  To  the  solution  in  dilute  hydrochloric  acid  add 
potassium  ferrocyanide  :  no  precipitate. 

5.  Treat  with  nitric  acid  :  it  will  turn  yellow  and 
dissolve. 

6.  To  a  solution  in  very  dilute  nitric  acid  add  lead 
acetate  or  mercuric  chloride  :  a  white  precipitate  will 
fall. 

7.  Dissolve  in   weak   hydrochloric  acid  or  caustic 
potash  and  boil:  no  precipitate  will  ensue. 

Pyocyanine. — 1.  Linen  stained  with  "blue  pus" 
must  be  extracted  with  cold  water  containing  a  little 
ammonia,  and  the  evaporated  and  filtered  extract 
digested  with  chloroform.  Shake  the  chloroform 


166  SAEKOSINE. 

solution  with,  very  weak  sulphuric  acid ;  treat  the  red 
aqueous  layer  with  baryum  carbonate,  and  baryta 
water  till  it  turns  blue,  filter,  shake  the  nitrate  with 
chloroform,  and  evaporate  the  chloroform  solution  in  a 
current  of  air.  Pyocyanine  will  gradually  deposit  in 
crystals  or  flakes. 

2.  It  is  soluble  in  water,  alcohol,  and  chloroform, 
but  almost   insoluble  in  ether.      Acids  turn  it  red; 
alkalies  blue.     It  is  decolorised  by  chlorine. 

3.  From  the  mother  liquor  of  pyocyanine,  a  yellow 
substance,  pyoxanthose,  may  be  obtained. 

Saliva. — 1.  Extract  ptyaline  by  the  method  described 
under  that  body. 

2.  Distil  with  a  dilute  acid  (phosphoric  or  sulphuric)  : 
in  the  distillate  ferric   chloride   will   produce    a   red 
colour,  showing  the  presence  of  sulpha-cyanide  (q.v.). 

3.  Evaporate  to  dryness  and  burn.      Analyse  the 
ash.     It  will  be  found  to  contain  calcium  carbonate. 

4.  If   the   saliva    be    turbid,    dilute    it   with    four 
volumes  of  water,  and   filter.     The  insoluble  matter 
will  be  tnucine.     (See  Mucine.) 

Sarkosine,  C3H7N02. — 1.  Boil  kreatine  with  baryta 
water  till  no  more  ammonia  is  given  off,  filter,  add  to 
the  filtrate  an  excess  of  dilute  sulphuric  acid,  boil,  and 
again  filter.  Evaporate  to  a  low  bulk,  mix  thoroughly 
with  three  or  four  successive  small  portions  of  cold 
alcohol,  decant  the  alcohol,  dissolve  the  residue  in 
water,  boil  with  baryum  carbonate  to  remove  sulphuric 


SUCCINIC   ACID.  167 

acid,  filter,  concentrate  to  a  syrup  at  100°  C.,  and  set 
aside  to  crystallise. 

2.  Sarkosine  is  very  soluble  in  water,  nearly  insolu- 
ble in  alcohol,  and  insoluble  in  ether.     Notice  neutral 
reaction  to  litmus  of  aqueous  solution. 

3.  Add  to  an  aqueous   solution  cupric  acetate  :  an 
intense  blue  colour  will  be  produced.      By  evaporation 
dark  blue  crystals  of  a  double  salt  may  be  obtained. 

4.  In  a  cold  saturated  solution  of  mercuric  chloride 
place  a  crystal  of  sarkosine  :  the  liquid  will  gradually 
solidify  to  a  network  of  white  needles. 

5.  To    a  solution  of   sarkosine    sulphate    add  lead 
peroxyde  ;  decomposition  with,  effervescence  will  take 
place,  and  the  solution  will  contain  metJiylamine. 

6.  Dissolve    sarkosine    in   hydrochloric    acid,     add 
platinic  chloride,  and  set  aside  to  evaporate.     Yellow 
octahedra  of  a  platinum  salt,  2  (C3H7N02,  HC1)  Pt014, 
2H30,  losing  water  at  100°,  will  be  deposited. 

7.  Heat  sarkosine  in  a  tube ;  it  will  melt  and  sub- 
lime without  residue. 

8.  Heat   another  portion  with   soda-lime :    methyl- 
amine  (with  a  smell  of  ammonia  and  alkaline  reaction) 
will  be  evolved. 

Succinic  acid,  C4H604. — 1.  Obtain  from  the  fluid  in 
the  bladders  of  echinococci  by  evaporating  to  a  syrup, 
adding  hydrochloric  acid  and  extracting  with  ether. 
The  ether  solution  after  distillation  leaves  succinic 
acid  in  crystals. 

2.  Heat  in  a  tube  open  at  both  ends.  The  acid  will 
sublime  in  silky  needles. 


168  SULPHOCYANIC    ACID. 

3.  It  is  soluble  in  water,  alcohol,  and  ether.     Dis- 
solve in  water,  and  use  for  the  following  reactions. 

4.  Neutralise  with  soda,  evaporate  to  crystallisation. 
Heat  a  portion  of  the    crystals   in    a   tube ;    it   will 
blacken,  leaving  a  residue  of  sodium  carbonate  mixed 
with  charcoal. 

5.  Neutralise  with  ammonia  and  add  ferric  chloride. 
A  bulky  red-brown  precipitate  will  be  formed,  easily 
soluble  in  mineral  acids.      Add  excess  of   ammonia, 
boil,  and  filter.     To  the  filtrate  add  baryum  chloride 
and  a  little  alcohol ;  a  white  precipitate  will  fall.     Ben- 
zoic  acid  will  give  no  "white  precipitate  under  these 
circumstances. 

6.  Add  lead  acetate ;  a  white  precipitate  will  ensue. 

Sulphocyanic  acid,  CNSH. — 1.  Obtain  by  distilling 
large  quantities  of  saliva  with  sulphuric  acid  and  neu- 
tralising the  distillate,  or  evaporate  the  saliva  to  dry- 
ness  and  extract  with  alcohol ;  evaporate  the  alcohol 
and  use  the  extract  dissolved  in  little  water.  Most 
sulphocyanides  are  soluble  in  water  and  alcohol. 

2.  Fuse  with  caustic  potash  ;  ammonium  carbonate 
will  be  evolved,  and  will  turn  red  litmus  blue.     Dis- 
solve the  residue  in  water  and  add  lead  acetate ;  a  black 
precipitate  of  sulphide  will  be  formed. 

3.  Heat   100   grammes  of  dry  ammonium   sulpho- 
cyanide  in   a  flask  to  170°C.  in  an  oil  bath  for  two 
hours.     Allow  to  cool  to  100°C.,  add  twice  its  bulk  of 
boiling  water,  filter  hot,  and  set  aside  to  crystallise. 
A  network  of  long  fibrous   satiny  crystals  of  sulphur 
urea  will  be  formed.     Press,  purify  by  recrystallisation 


SWEAT.  169 

from  water  and  from  alcohol,  dissolve  a  small  quantity 
in  a  very  large  bulk  of  water,  and  apply  the  following 
tests. 

a.  Add  a  drop  of  cuprous  chloride  in  hydrochloric 
acid ;  a  bulky  white  gelatinous  precipitate  will 
appear. 

I).  Add  mercuric  nitrate ;  an  amorphous  white 
precipitate  will  fall. 

c.  Add  cupric  sulphate ;  a  precipitate  of  white 
microscopic  prisms  will  gradually  form,  redis- 
solved    by  heat  and   depositing   again  in  oily 
drops  or  in  crystals  on  cooling,  giving  by  long 
boiling  a  black  precipitate  of  sulphide. 

d.  Add  ferric  chloride ;  no  reaction  if  the  urea  be 
pure. 

4.  Boil  a  sulphocyanide  with  nitric  acid ;  a  yellow 
precipitate  of  persulphocyanogen  will  be  produced. 

5.  To  a  sulphocyanide  solution  add  ferric  chloride  ; 
an  intense  red  colour  will  be  produced.     Add  a  frag- 
ment of  pure  zinc,  and  suspend  over  it  a  slip  of  paper 
moistened    with   lead   acetate.       The   paper    will   be 
blackened  by  the  evolution  of  H3S. 

6.  Add  solution  of  cuprous  chloride  in  hydrochloric 
acid  ;  a  white  granular  precipitate  will  appear. 

Sweat. — 1.  Notice  appearance,  smell,  acid  reaction, 
and  presence  of  epidermic  scales. 

2.  Distil  down  to  a  third  or  fourth  with  a  little 
dilute  sulphuric  acid.  Examine  the  distillate  for 
volatile  acids  (q.v.).  Digest  the  residue  in  the  retort 
with  ether. 


170  SYNTONINE. 

3.  Evaporate  the  ethereal  solution  freed  from  sul- 
phuric acid  by  digestion  with  carbonate  of  baryta,  and 
exhaust  with    water.      The    aqueous    solution    freed 
from  baryta  by  cautious  precipitation  with  sulphuric 
acid  examine  for  lactic    acid   and  urea  (q.  v.).      The 
insoluble  portion  will  consist  of  fats  (q.  v.). 

4.  Examine  the  portion  insoluble  in  ether  for  urea, 
uric  acid,  sugar,  and  sudoric  acid. 

5.  Heat  a  little  of  the  sweat  to  boiling ;    a  flaky 
precipitate    of    albumen   will,   in    some    rare    cases, 
appear. 

6.  Evaporate  to  dryness,  burn,  and  analyse  ash. 

Synovia. — 1.  Notice  appearance  and  alkaline  re- 
action. 

2.  Dilute  with  two  volumes  of  water,  add  acetic 
acid  till  very  slightly  acid,  and  boil.     A  precipitate  of 
albumen  will  be  formed. 

3.  Evaporate  to  a  low  bulk  at  100°C.  and  exhaust 
with  ether.     The   ether  on  evaporation   will  leave  a 
residue  of  fat. 

4.  Evaporate  to  dryness  and  burn.     Analyse  ash. 

Syntonine  or  Muscle-fibrine. — 1.  Wash  comminuted 
muscle  with  cold  water  till  free  from  albumen,  digest 
with  very  dilute  hydrochloric  acid,  strain,  neutralise 
the  solution  with  sodium  carbonate,  and  wash  with 
water  the  precipitate  of  syntonine. 

2.  The  reactions  are  similar  to  those  of  fibrine, 
except  that  it  is  more  soluble  in  dilute  hydrochloric 
acid. 


TAUROCHOLIC   ACID.  171 

Taurine,  C2H7NS03. — 1.  Mix  ox  bile  with  hydro- 
chloric acid,  filter  the  liquid  from  the  precipitate  which 
will  fall,  evaporate  the  filtrate  till  it  separates  into  a 
viscous  resin  and  a  watery  liquid ;  pour  off  the  liquid 
and  rinse  the  resin  with  water.  Unite  the  two  liquids, 
and  evaporate  to  a  small  bulk ;  allow  to  crystallise ; 
taurine  and  sodium  chloride  crystallise  out ;  the 
taurine  is  separated  by  picking  out  the  crystals,  which 
can  be  purified  by  recrystallisation. 

2.  Taurine  crystallises  in  large  transparent  glassy 
crystals,    which   when   heated   first    melt    and    then 
blacken.      It  is  moderately  soluble  in  water,   nearly 
insoluble  in  alcohol. 

3.  Melt  some  taurine  with  caustic  potash ;    treat 
the  residue  with   dilute  sulphuric,  holding  a  slip  of 
paper  moistened  with  lead  acetate  solution  over  the 
mass ;  sulphuretted  hydrogen  is  evolved,  turning  the 
lead  paper  black  ;  sulphurous  acid  is  also  evolved,  and 
sulphur  is  left  as  a  residue.     This  proves  the  existence 
of  sulphur  in  taurine. 


Taurocholic  acid,  C26H45NS07. — 1.  Extract  some 
dog's  bile  with  alcohol,  decolorise  by  animal  charcoal, 
and  evaporate  the  extract  to  dryness.  Dissolve  the 
residue  in  a  small  quantity  of  absolute  alcohol  and 
ether ;  on  standing  in  the  cold  sodium  taurocholate  is 
precipitated  in  crystals. 

2.  Precipitate  ox  bile  with  neutral  lead  acetate,  and 
filter.  Precipitate  with  basic  lead  acetate,  and  wash 
the  collected  precipitate  ;  dissolve  it  in  boiling  alcohol, 


172  TYRO  SINE. 

and   decompose   with   hydrothion.     The    solution    on 
evaporation  leaves  amorphous  taurocholic  acid. 

3.  Taurocholate  of  sodium  is  not  precipitated  by- 
acids  but  by  caustic   potash.     Its  solution  in  water 
froths  like  soap-lather.     It  is  not  precipitated  by  neu- 
tral lead  acetate. 

4.  By  boiling  with  hydrochloric  acid  it  is  decom- 
posed, yielding  taurine,  cJioloidic  acid,  and  dyslysine. 

5.  By  boiling  with  excess  of  caustic  baryta  it  is  also 
decomposed,   yielding  taurine  and  cJwlic  acid,   which 
latter  remains  in  combination  with  the  baryum. 

6.  On  fusion  with   caustic  potash  taurocholic  acid 
and  taurocholates    behave   like    taurine   (3),   forming 
sulphides,  which  are  decomposed  by  acids  under  evo- 
lution of  hydrothion. 

7.  Determine  the  quantity  of  taurocholic  acid  by  the 
process  Bile,  14. 

Trimethylamine,  C3H9N. — 1.  Distil  urine  with  lime; 
saturate  the  alkaline  distillate  with  sulphuric  acid, 
evaporate  to  dryness,  and  extract  with  absolute 
alcohol.  Trimethylamine  sulphate  if  present  dissolves, 
and  maybe  purified  by recrystallisation,  and  the  trime- 
thylarnine  liberated  by  distillation  with  potash. 

2.  To  a  little  of  the  sulphate  add  calcium  hydrate  in 
powder,  and  warm.  Trimethylamine  will  be  disen- 
gaged, with  a  peculiar  odour  of  bad  fish. 

Tt/rosine,  C9HnN03. — 1.  Boil  horn  shavings  with 
twice  their  weight  of  dilute  sulphuric  acid  (one  part  of 
concentrated  sulphuric  acid  and  four  parts  of  water) 


UKEA.  173 

for  four  hours,  renewing  the  water  as  it  evaporates. 
Dilute  with  water,  add  an  excess  of  milk  of  lime,  and 
strain,  exhausting  the  residue  with  boiling  water. 
Evaporate  the  filtrate  and  extracts  to  about  two  thirds 
of  the  bulk  of  the  dilute  sulphuric  acid.  Neutralise 
with  sulphuric  acid,  and  allow  the  whole  to  stand. 
Impure  tyrosine  crystallises  out. 

2.  Purify  and  decolorise  by  dissolving  the  tyrosine 
in  a  little  hydrochloric  acid  and  boiling  the  solution 
with   animal    charcoal.      Filter    and    precipitate    the 
tyrosine  by  adding  acetate  of  soda  solution.     Crystal- 
lise the  tyrosine  by  dissolving  in   a  little  hot  strong 
ammonia,  and  allowing  to  cool,  when  the  tyrosine  will 
separate  out  in  white  acicular  tufts. 

3.  Tyrosine  is  moderately  soluble  in  boiling  water, 
very  sparingly  soluble  in  cold  water,  almost  insoluble 
in  alcohol,  it   is  easily   soluble   in  hydrochloric   acid, 
ammonia,  &c. 

4.  To  a  small  portion  of  tyrosine  add  a  little  Nord- 
hausen  sulphuric  acid ;  the  tyrosine  dissolves,  let  stand 
for   some  time;  dilute  rapidly  with  water,  neutralise 
the  solution  with  baryum  carbonate,  filter,  add  to  the 
filtrate  some  neutral  solution  of  ferric  chloride  when  a 
violet  colour  is  produced. 

5.  Heat  some  tyrosine  in  a  glass  tube,  it  decom- 
poses, evolving  a  strong  agreeable  smell. 

6.  Add  to  an  aqueous   solution  of  tyrosine  a  little 
mercuric  nitrate  with  mercurous  nitrate,  a  pink  colour 
and  red  precipitate  will  be  produced  on  warming. 

Urea,  CH4N20. — 1.  Evaporate  urine  to  dryness  on 


174  UEEA. 

a  water-bath ;  exhaust  the  residue  with  hot  alcohol ; 
evaporate  the  solution  to  dryness;  take  up  with 
absolute  alcohol;  evaporate  the  solution  to  .dryness, 
when  crystals  of  urea  will  be  obtained. 

2.  Evaporate  a  solution  of  cyanate  of  ammonium  to 
dryness  on  a   water-bath;    crystals  of  urea   will  be 
obtained. 

3.  Urea  is  very  soluble  in  water,  and  alcohol,  nearly 
insoluble  in  ether ;  on  heating,  it  melts  and  then  de- 
composes.     Examine  the  crystals  under   the   micro- 
scope. 

4.  Take  a  small  quantity  of  urea,  dissolve  in  water, 
add  a  saturated  solution  of  sodium  carbonate,  place 
the  whole  in  a  flask,  and   distil  through   a  Liebig's 
condenser  previously  well  washed  with  distilled  water ; 
collect  the  distillate ;    on  adding  some  Nessler   test- 
solution   a   dark-brown    colour    will  be    immediately 
formed,  proving  the  decomposition  of  the  urea  into 
ammonia  and  carbonic  acid. 

5.  Add  to  an  aqueous  solution  of  urea  a  solution  of 
nitrate  of  mercury;  a  white  precipitate  of  mercuric 
oxyde  and  nitrate  of  urea  falls. 

6.  Half  fill  a  test-tube  with  an  aqueous  solution  of 
urea,  fill  up  the  tube  with  a  solution  of  hypochlorite, 
close  the  test-tube  with  the  thumb,  invert  the  whole 
once  or  twice   to  mix  the  contents  thoroughly,  and, 
finally,  invert  the  tube  under  the  surface  of  a  saturated 
aqueous  solution  of  salt.     Allow  to  stand ;  bubbles  of 
gas  will  soon  be  disengaged,  and  collect  in  the  upper 
part  of  the  test-tube.      This  gas  is  nitrogen  formed 
from  the  decomposition  of  the  urea. 


ESTIMATION   OF    UREA.  175 

7.  Add  to  a  concentrated  solution  of  urea  nitric 
acid;  crystals  of  urea  nitrate  will  immediately  form. 
Add  oxalic  acid  to  urea,  and  the  oxalate  will  be 
deposited. 

Estimation  of  urea. — 1.  Dissolve  in  a  beaker  100 
grammes  of  pure  mercury  in  about  500  grammes  of 
pure  nitric  acid ;  add  a  further  quantity  of  nitric  acid 
in  drops,  gently  shaking  occasionally  until  no  red 
vapours  are  evolved  either  on  the  addition  of  nitric 
acid  or  on  shaking ;  then  evaporate  the  solution  at  a 
gentle  heat  until  it  is  a  colourless  syrup.  Care 
must  be  taken  that  none  of  the  liquid  is  lost  by 
spurting. 

2.  Dilute  the  solution  to  exactly  1400  c.c.,  adding  a 
little  nitric  acid  to  prevent  the  formation  of  an  in- 
soluble basic  salt.     This  forms  the  standard  solution  of 
nitrate  of  mercury,    each    cubic  centimetre  of  which 
represents  a  centigramme  of  urea.    To  be  certain  of  its 
strength  a  test   experiment    should  be   made   by  es- 
timating a  known  quantity — about  two  decigrammes — 
of  pure  urea  as  described  hereafter. 

3.  Prepare  cold  saturated  solutions  of  baryta  water 
and  baryum  nitrate ;  mix  two  volumes  of  baryta  water 
with  one  volume  of  nitrate  of  baryum  solution.     This 
mixture  forms  the  baryta  solution  used  in  the  analysis. 

4.  On  a  glass  plate  under  which  is  a  piece  of  white 
filter  paper,  place  a  number  of  small  drops  of  carbonate 
of  soda. 

5.  Add  to  30  c.c.  of  urine   15  c.c.  of  the  baryta 
solution ;  mix  well  with  a  stirring-rod,  and  filter  through 


176  URIC   ACID. 

a  dry  filter  paper.  Measure  off  15  c.c.  of  the  filtrate 
(=10  c.c.  of  urine)  into  a  small  beaker,  add  the  standard 
nitrate  of  mercury  solution  from  a  burette  or  other 
graduated  vessel  until  a  drop  of  the  mixture  when 
added  to  a  drop  of  carbonate  of  soda  solution  on  the 
glass  plate  produces  a  distinct  yellow  colour  in  two 
seconds.  When  this  colour  appears  read  off  the 
number  of  cubic  centimetres  used ;  each  cubic  centi- 
metre required  indicates  1  centigramme  of  urea  in  the 
10  c.c.  of  urine.  Thus,  if  25  c.c.  of  mercury  solution 
were  used  there  would  be  25  centigrammes  or  0*25 
grin,  in  10  c.c.  or  25  grm.  in  the  litre. 


Uric  acid,  C5H4N403. — 1.  Obtain  from  human  urine 
by  adding  to  it  -^  hydrochloric  acid,  let  stand  in  a 
warm  place  at  first,  afterwards  in  the  cold,  and  collect 
the  precipitate  of  crystallised  coloured  acid.  Purify  as 
described  in  2. 

2.  Obtain  from  excrements  of  serpents  by  dissolving 
them  in  hot  caustic    soda   ley,  boiling  to   expel  am- 
monia, precipitating   urate  by  a  current  of  carbonic 
acid,  dissolving  the  urate  in  caustic  soda,  and  pouring 
this   solution  in  hot  dilute  hydrochloric  acid.     White 
uric  acid  in  crystals  is  deposited. 

3.  Observe  its   forms  of  crystallisation   under    the 
microscope,  and  make  yourself  acquainted    with  the 
principal  typical  forms  (rhombic    prisms   and  plates) 
which  the  acid  assumes,  particularly  when  it  is  depo- 
sited spontaneously  in  the  urinary  passages  or  in  the 
urine  after  emission. 


UEIC   ACID.  177 

4.  Dissolve  uric  acid  in  boiling  water,  and  observe 
that  a  deposit  ensues  on  cooling.     Dissolve  it  in  alka- 
lies, and  observe  that  the  salts  with  excess  of  alkali 
are  much  more  soluble  than  the  salts  with  excess  of 
acid. 

5.  Dissolve  one  part  of  uric  acid  in  four  parts  of 
nitric  acid  of  1*42  sp.  gr.     The  acid  will  dissolve  under 
evolution  of  carbonic  acid,  nitrogen  and  nitrous  acid, 
and  on  cooling   alloxan  (see  p.  67)  will  be  deposited. 

6.  Evaporate  the  solution  of  uric  in  nitric    acid  to 
dryness  on  the  water  bath,  and  allow  the  vapour  of 
ammonia  to  touch  the  residue.     A  purple  colour  of 
murexide  will  be  produced. 

7.  To  uric  acid  made   into  a  pap  with  water  add 
gradually  lead  peroxide,  and  keep  the  mixture  near  the 
boiling  point.     The  lead  is  transformed  into  oxalate, 
carbonic  acid  is  evolved  with  effervescence,  the  filtered 
fluid  deposits  crystals  of  allantoine  on  cooling,  and  the 
mother  liquid  contains  urea. 

8.  Heat  uric  acid  in  closed  tubes  with  concentrated 
hydrochloric  or  hydriodic  acid,  and  obtain   glykoltoll  by 
decomposition  of  the  resulting  salt  as  described  under 
that  substance. 

9.  Examine  the  urates  spontaneously  deposited  on 
cooling  from  healthy  or  morbid  urine ;  collect  them  on 
a  filter,   and    observe  that  when  washed  with  water 
crystals  of  uric  acid  gradually  form  in  them,  but  that 
this  formation  does  not  take  place  when  the  washing  is 
effected  with  spirit.     Determine  the  quantity  of  bases 
contained  in  them,  which  are  mostly  a  mixture  of  potash, 
soda,   and  ammonia,  and  notice  that    their  collective 

12 


178  UEINE. 

basic  value  only  amounts  to  about  one  half  of  what  the 
whole  of  the  uric  acid  would  require  to  be  in  the 
condition  of  acid  urate.  These  deposits  are  therefore 
hyper-acid  urates. 

Urine,  systematic  analysis. — Test  the  action  of  the 
urine  with  litmus. 

I.  It  is  acid  and  has  no  sediment,  proceed  to  2. 

II.  It  is  acid  and  has  a  sediment ;  pour  off  the  clear 
liquid,  filtering,  if  necessary,  and  proceed  to  ana- 
lyse the    filtrate  according  to  2.     Examine   the 
sediment  dry. 

1.  Heat  a  sample  of  urine  to  boiling  after  the 
addition  of  some  acetic  acid.  A  coagulum 
forms,  which  does  not  disappear  on  the  addition 
of  nitric  acid  :  albumen. 

Boil  some  quantity  (500  c.c.)  of  the  urine 
with  acetic  acid ;  filter  off  the  coagulated  albu- 
men and  treat  the  filtrate  as  under  2. 

a.  The  coagulum  is  white,  pure  albumen. 

b.  The  coagulum  is  greenish  :  albumen,  probably 
coloured  by  bile. 

c.  The    coagulum   is   brownish-red :    probably 
from  blood ;  wash  and    dry  the    coagulum ; 
boil  with  alcohol  containing  a  little  sulphuric 
acid ;  if  the  filtrate  is  reddish   examine  with 
spectroscope  for  acid  hecnatine  or  evaporate 
to  dryness,  ignite,  moisten  the  ash  with  a 
drop  or   two    of   concentrated   hydrochloric 


TJEINE.  179 

acid,  dilute  with  a  little  water,  filter  the 
solution  through  a  small  filter,  and  add  to  the 
filtrate  a  little  potassium  sulphocyanide ;  a 
red  colour  confirms  the  presence  of  blood. 

2.  Take  4  to  500  c.c.  of  the  clear  urine  filtered  from 
coagulated  albumen  or  sediment ;  evaporate  in 
a  porcelain  dish  or  a  water-bath  to  a  thick 
syrup ;  divide  the  syrup  into  two  parts,  one 
equal  to  one  3rd  the  other  two  3rds  of  the  whole. 

a.  Extract  the  3rd  with  strong  alcohol ;  filter, 
and  examine  the  filtrate. 

1.  Evaporate  a  small  portion  nearly  to  dry- 
ness  and  add  a  little  nitric  or  oxalic  acid, 
and   observe  the  crystalline  forms  of  urea 
nitrate  or  oxalate. 

2.  Precipitate  the  larger  portion  with  a  few 
drops  of  milk  of  lime  and  calcium  chloride 
solution  and  filter  ;  concentrate  the  filtrate 
on  the  water-bath  to  10-12  c.c.    Transfer  to 
a  beaker,  add  one-half  c.c.  of  strong  alcoholic 
solution  of  zinc  chloride,  stir  well  and  allow 
to  stand ;  kreatinine  chloride  of  zinc  crys- 
tallises out  in  warty  grains. 

b.  Acidify   the    two -thirds    with    hydrochloric 
acid,  and  extract  with  ether.     Evaporate  the 
ethereal  solution  and  examine  the  residue  for 
hippuric  acid. 

1.  The  filtrate  will  contain  earthy  phosphate 
and  other  salts  ;  add  ammonia ;  the  earthy 
phosphates  will  be  precipitated. 


180 


URINE. 

2.  The   insoluble  residue  consists  of  mucus 
and  uric  acid.     Wash  off  the  filter  into  a 
test  tube,  add  one  or  two  drops  of  caustic 
soda,  warm  and  filter.     The  insoluble  resi- 
due is  mucus.     The  filtrate  contains  uric 
acid  and  hydrochloric  acid ;  the  Uric  acid 
separates    out    in    crystals ;    collect    and 
examine  under  the  microscope,  also  verify 
by  applying  the  murexide  test,  the  presence 
of  uric  acid. 

3.  The  urine  is  brown  or  green ;  froths  on 
shaking ;  colours  a  small  piece  of  immersed 
filter-paper    yellow    or    green;    probable 
presence  of  bile  matter. 

Place  some  of  the  urine  upon  a  white 
plate  and  drop  in  a  little  strong  nitric  acid 
containing  some  nitrous,  without  shaking. 
The  fluid  turns  successively  green,  blue, 
violet,  and  brown ;  presence  of  a  derivate 
of  colouring  matter  of  the  bile. 

To  a  second  portion  add  some  lead 
acetate  in  solution ;  collect  the  precipitate, 
wash,  dry,  and  boil  the  dried  precipitate 
with  alcohol,  to  which  a  little  sulphuric 
acid  has  been  added,  filter ;  the  filtrate  is 
green  from  biliprasine. 

Evaporate  a  third  portion  of  3  to  500  c.c. 
on  the  water-bath,  extract  with  alcohol; 
search  for  biliary  acids,  tauro-  and  glyko- 
cholic. 


TJEINE.  181 

4.  Take  1  c.c.  of  urine,  dilute  it  with  4  to  5 
c.  c.  of  water,  add  ^  a  c.  c.  of  caustic  soda, 
and  one  drop  of  a  very  dilute  solution  of 
copper  sulphate  ;  boil ;  a  red  granular  pre- 
cipitate of  suboxyde  of  copper  indicates  the 
presence  of  sugar. 

5.  Immerse   in   the  urine   a  piece  of  filter- 
paper  moistened  with  acetate  of  lead  solu- 
tion, if  the  lead  paper  turns  brown  or  black 
sulphuretted  hydrogen  is  present. 

6.  Evaporate  40  to  50  c.  c.  of  the  urine  to 
dryness,  ignite  the  residue  at  a  moderate 
heat  till  all  the  charcoal  has  been  burnt 
off;  boil  the  residue  with  water  and  filter. 

a. — 1.  Acidify  a  portion  of  the  filtrate 
with  hydrochloric  acid ;  add  baryum 
chloride;  a  white  precipitate  proves  the 
presence  of  sulphuric  acid. 

2.  Acidify  a  second  portion  with  nitric 
acid,  add  a  drop  of  silver  nitrate  ;  a  white 
curdy     precipitate    indicates    hydrochloric 
acid. 

3.  Acidify   a   third  portion   with  acetic 
acid,  add  a  little  ferric  chloride   solution,  a 
yellowish-white,  gelatinous  precipitate  in- 
dicates phosphoric  acid. 

4.  Evaporate  the  rest  to  dryness ;  take 
up  a  small  portion  on  the  end  of  a  platinum 
wire  and  expose  in  a  Bunsen  or  spirit  lamp 


182  UEINE. 

flame;  a  vivid  yellow  colour  proves  the 
presence  of  sodium. 

5.  Dissolve  a  portion  in  a  little  water, 
add  a  drop  or  two  of  solution  of  platinic 
chloride ;  a  yellow  crystalline  precipitate 
indicates  potassium. 

b.  Boil  the  residue  insoluble  in  water 
with  a  little  dilute  hydrochloric  acid,  filter. 

1.  Boil  a  portion  with  a  drop  of  nitric 
acid,   add  some    potassium  sulphocyanide 
solution  ;  a  deep  red  colour  proves  presence 
of  iron. 

2.  Mix  the  rest  with  an  excess  of  sodium 
acetate,  add  an  excess  of  ammonium  oxa- 
late ;      a     white    precipitate     proves    the 
presence  of  calcium. 

3.  Filter  off  the  lime  precipitate,  add  to 
the  filtrate  ammonia;  a  white  crystalline 
precipitate     indicates      the     presence    of 
phosphate  of  magnesia. 

7.  Add  to  50  or  100  c.  c.  of  the  fresh  urine 
contained  in  a  flask,  a  little  milk  of  lime, 
mix  and  cork  loosely,  suspending  a  mois- 
tened red  litmus  paper  between  the  cork 
and   the  side  of   the  flask.     If  the  paper 
turns    blue  the   presence    of   ammonia    is 
proved. 

8.  Distil  some  urine  with  sulphuric  acid,  add 
to  the  distillate  a  little  red  fuming  nitric 
acid,  and  then  shake  up  with  a  drop  of 


URINE.  183 

carbon  disulphide,  which,  if  iodine  be  pre- 
sent, will  be  coloured  pink. 
For  acetic,  benzoic  and  kryptophanic  acid,  and 
for  urochrome  and  its  products,  see  sepa- 
rate articles. 

Examination  of  the  Sediment. — Allow  any  sediment 
to  deposit  at  the  bottom  of  a  conical  glass. 
Pour  off  as  much  of  the  liquid  as  possible, 
then  take  up  a  little  sediment  with  a  pipette,  place 
on  a  glass  slide,  and  examine  with  the  micro- 
scope. 

A.  The  urine  is  acid. 

I.  The  whole  of  the  sediment  seems  amorphous. 

1.  On    gently  warming   the  whole    dissolves: 
urates ;  confirm  by  adding  a  drop  of  hydro- 
chloric acid ;  leave  half  an  hour,  when,  if  uric 
acid  be  present,  it  will  have  crystallised  out 
in  rhombic  tables. 

Also  confirm  by  the  murexide  test. 

2.  The  sediment  does  not  dissolve  on  warming, 
but  dissolves  in  a  drop  of  acetic  acid  without 
effervescence  ;  presence  of  calcium  phosphate. 

3.  Glistening  drops  appear  in  the  sediment  and 
disappear    on    the    addition  of    ether :   fat 
globules. 

II.  The  sediment  contains  well-formed  crystals. 

1.     Small,     glistening,  transparent    octohedra, 
insoluble  in  acetic  acid  :  calcium  oxalate. 


184 


URINE. 

2.  4-sided  tables  or    6-sided    rhombic    plates 
often    appearing     grouped    in     bunches    of 
spindle-shaped  crystals  :  uric  acid  ;  confirm  by 
the  murexide  test. 

3.  Regular    6-sided   tables   soluble   in    hydro- 
chloric acid  and  ammonia,  which    char   on 
heating.     Boil  with  caustic  soda  containing 
a  drop  of  very  dilute  acetate  of  lead ;  a  black 
precipitate  of  sulphide  of  lead  confirms  the 
presence  of  cystine. 

4.  Wedge-shaped     prismatic     crystals,    some 
separate,  some  united,  to  form  a  cross  :  cal- 
cium phosphate. 

5.  Greenish-brown  grains  with  a  radiating  crys- 
talline structure :  tyrosine. 

6.  Needles  or  rhombic  prisms  easily  soluble  on 
warming  :  hippuric  acid. 

III.  The  sediment  contains  organised  bodies. 

1.  Twisted    fringy   bundles,   forming    points, 
grains,  &c. :  mucus. 

2.  Contracted  granular  bodies,  often  united  into 
a    scale     pavement-like    mass :    mucus    cor- 
puscles. 

3.  Circular  biconcave  disks,  mostly  yellowish, 
which  swell  up  and  more  or  less  completely 
dissolve    in    acetic   acid :     blood-corpuscles ; 
confirm  by  spectroscopic  reactions. 

4.  Round,  pale,  faintly-granular  vesicles,  of  dif- 
ferent sizes,  which  swell  up  considerably  in 
acetic  acid,  lose  their  outward  granular  sur- 


URINE.  185 

face,  and  allow  an  inner  nucleus  of  different 
form  to  be  seen  :  pus. 

5.  Cylindrical  masses  with,  small  vesicles,  often 
mixed  with   blood-    and  pus -corpuscle's :  so- 
called  casts  of  the  tubules. 

a.  Casts  whose  roundish  nuclei  are  clearly 
visible    through    a    delicate    surrounding 
mass :    epithelial    casts  of  Bellini's    tubes, 
mostly     accompanied    by    the    nucleated, 
epithelial  cells  of  ureters  and  kidneys. 

b.  Solid  cylinders  of  thick,  granular,  nucle- 
ated nature  are  granular  renal  casts9  and 
often   contain    blood-   and   pus -corpuscles 
with    fat    globules,    crystals   of    calcium 
oxalate. 

c.  Pale,   transparent,    solid   cylinders,    only 
seen  with  great  difficulty  :  hyaloid  casts. 

6.  Epithelial  cells. 

a.  Pavement  epithelium. 

b.  Epithelial  tubes. 

7.  Fermentation  and  thread  fibres. 

8.  Short  fine  rods,  threads,  or   square  lumps, 
moving    about    in    an    undulating    manner : 
Vibrios,  Spermatozoa,  Sarcina  ventriculi. 

B.  The  urine  is  alkaline. 

I.  Crystalline  sediment. 

1.  Rhombic  vertical  prisms  soluble  in  acetic  acid; 
on  mixing  with  a  little  milk  of  lime  ammonia 
is  evolved:  ammonio-magnesian phosphate. 


186  UROCHEOME. 

2.    Wedge-shaped   opaque   masses   giving  the 
murexide  reaction  :  ammonia  urate. 

II.  Sediment  is  amorphous,  usually  calcium  phos- 
phate. 

III.  Sediment    contains    organised    bodies,    see 
above  under  A  III. 

Urine  Oil  or  Essential  Oil  of  Urine. — 1.  The  distillate 
from  urine  with  sulphuric  or  phosphoric  acid  (see 
Uromelanine)  must  be  neutralised  with  sodium  car- 
bonate, evaporated  to  a  rather  low  bulk,  and  extracted 
repeatedly  with  small  quantities  of  ether. 

2.  The  aqueous  solution  contains  salts   of  volatile 
acids  (q.v.). 

3.  Distil  off  the  ether  from  the  ethereal  solution  ;  a 
residue  of  essential  oil  will  remain,  with  a  yellowish 
colour  and  a  powerful  urinous  smell. 

4.  It  is  little  soluble  in  water,  becoming  milky  when 
mixed  with  it,  soluble  in  ether  and  alcohol. 

5.  "Warm  with  mercuric  nitrate   solution ;  a  purple 
colour  will  be  produced. 

6.  Boil  with  silver  nitrate ;  no  reduction  will  take 
place. 

Urochrome. — 1.  Fresh  urine  is  treated  with  excess 
of  milk  of  lime  or  baryta,  allowed  to  stand,  and 
filtered.  To  the  filtrate  lead  acetate  with  a  little 
ammonia  is  added  till  colourless,  and  the  preci- 
pitate well  washed  and  digested  with  cold  dilute 
sulphuric  acid  till  a  filtered  sample  shows  an 
excess  of  sulphuric  acid  when  tested  with  baryum 


UKOCHEOME.  187 

chloride  and  hydrochloric  acid.  At  this  point  filter 
the  whole,  shake  the  filtrate  with  baryum  carbonate  to 
remove  the  sulphuric  acid,  add  a  little  baryta  water, 
pass  carbonic  acid  through  the  liquid  and  filter  again. 
Precipitate  the  solution  with  mercuric  acetate,  wash 
the  precipitate  of  urochrome  mercury  very  thoroughly 
with  cold  and  hot  water,  decompose  it  by  sulphuretted 
hydrogen,  filter,  shake  the  filtrate  with  a  little  fresh 
silver  oxyde  to  remove  hydrochloric  or  kryptophanic 
acid,  filter ;  again  decompose  by  sulphuretted  hydro- 
gen, and  evaporate  the  filtrate  to  dryness  in  vacuo 
over  sulphuric  acid.  A  yellow  uncrystallisable  mass 
of  urochrome  remains. 

2.  Urochrome   is    easily   soluble  in  water    with    a 
yellow  colour,  very  little  soluble  in  alcohol,  soluble  in 
ether,  and  can  thereby  be  separated  from  kryptophanic 
acid,  which  is  insoluble  in  ether. 

3.  To  the  solution  in  water  add  lead  or  mercuric 
acetate  :  a  flaky  yellowish  precipitate  will  fall. 

4.  Add  silver  nitrate :  a  gelatinous  precipitate  solu- 
ble in  nitric  acid,  will  form. 

5.  Add  mercuric  nitrate  :  a  white  precipitate,  pale 
flesh-coloured  on  boiling,  will  be  produced. 

6.  The  aqueous  solution  on  standing  becomes  red 
and  deposits  resinous  flakes,  containing  uromelanine, 
uropittine,  omicholine,  and  omicholic  acid  (q.v ).     This 
decomposition  is  hastened  by  boiling  and  by  acids. 

7.  Treat  acidified    extract  of  urine  by  ether,  and 
distil  the  latter.      Precipitate  the  residue  by  basic  lead 
acetate,  decompose  by  hydrothian,  and  treat  urochrome 
as  above. 


188 


UEOMELANINE. 


8.  Separate  kryptophanic  acid  by  dissolving  its 
lead- salt  in  excess  ©f  lead  acetate,  in  which  urochrome 
lead  is  insoluble. 


Urocyanine. — Urine  from  cholera  patients  in  the 
early  stage  of  reaction,  is  cautiously  boiled  with  nitric 
acid.  A  blue  colour  is  often  produced,  and  a  blue 
deposit  sometimes  formed.  The  latter  is  soluble  in 
alcohol,  forming  a  dichroic  purple  blue  solution  giving, 
before  the  spectroscope,  a  broad  absorption  band  in 
yellow  and  green. 


AaBC 


AaBC         D 


Spectrum  of  choleraic  urocyanine. 


Eb        F 


HH' 


Spectrum  of  choleraic  urorubine. 


Uromelanine,  C36H43N7010. — 1.  Evaporate  fresh  urine 
to  one  tenth,  filter,  evaporate  the  nitrate  to  a  syrup,  and 
set  aside  to  crystallise.  Decant  the  mother  liquor, 
dilute  with  one  volume  of  water,  and  treat  with 


UROMELANINE.  189 

calcined  magnesia  till  a  filtered  sample  is  free  from 
phosphoric  acid.  Filter  the  whole,  and  to  the  solution 
add  some  concentrated  sulphuric  acid  drop  by  drop, 
shaking  well,  until  strongly  acid.  Filter  and  distil  in 
a  retort  for  six  hours,  replacing  the  water  as  it  evapo- 
rates, and  adding  more  sulphuric  acid  if  necessary. 
The  distillate  will  contain  volatile  acids  (q.  v.)  and 
essential  oil  (q.  v.) 

2.  The  residue  in  the  retort  must  be  mixed  with  two 
volumes  of  water  and  allowed  to  stand.     A  brown-red 
resinous  precipitate  will  be  formed.     Filter. 

3.  Evaporate    down    the  nitrate,  again  precipitate 
with   water   and   filter,    and    again    concentrate    and 
allow  to  stand ;  crystals  of  hippuric  acid  will  probably 
be  deposited  (q.  v.). 

4.  The  resinous  precipitate  is  well  washed  with  cold, 
then  with  boiling,  water,  and  boiled  with  90%  alcohol. 
Omicholine,  omicholic  acid,  and  uropittine  (q.  v.)  dissolve 
in  the  alcohol,  while  uromelanine  remains  as  an  in- 
soluble black  powder. 

5.  Wash  the  uromelanine  with  boiling  alcohol,  then 
with  water,  dissolve  in  very  weak  caustic  potash,  filter, 
acidify  with  dilute  sulphuric  acid,  wash  the  precipitate 
with  water  and  hot  alcohol,  and  dry. 

6.  Uromelanine   is   insoluble    in   water    and   dilute 
acids,  very  slightly  soluble  with  a  red  colour  in  alcohol, 
extremely    soluble     with    a    brown-black    colour    in 
alkalies. 

7.  Dissolve  in  acetic  acid,  and  add  to  the  solution 
mercuric  nitrate.     A  red  precipitate  will  appear. 

8.  Dissolve  in  concentrated  sulphuric  acid,  mix  the 


190  XANTHINE. 

red  solution  with  water.  The  uromelanine  will  be 
completely  precipitated,  leaving  the  liquid  colourless. 
Allow  another  portion  of  the  red  solution  to  stand 
some  hours,  then  mix  with  water ;  a  precipitate  will 
be  produced,  but  the  liquid  will  be  coloured. 

9.  Distil  dry  uromelanine  :  a  neutral  oily  distillate 
will  pass  over,  containing  no  aniline.  Add  a  drop  of 
mercuric  nitrate ;  a  red  colour  and  precipitate  will  be 
produced. 


Uropittine. — 1.  The  matter  insoluble  in  ether  (see 
Omicholine)  must  be  boiled  with  absolute  alcohol  and 
filtered ;  the  filtrate  on  cooling  will  deposit  uropittine 
in  granules,  which  may  be  purified  by  again  dissolving 
in  alcohol  and  cooling. 

2.  Uropittine  is  a  brown  resin,  fusing  in  hot  water 
but  insoluble  in  it,  slightly  soluble  in  alcohol,  insoluble 
in  ether. 

3.  It  is  more  soluble  in  boiling  than  in  cold  alcohol, 
and    is  obtained  as  a  resin  by  evaporation,  or  as  a 
powder  by  precipitation  with  ether  or  with  water. 

4.  Dissolve   in   little   ammonia,    and   add   calcium- 
chloride  :    a   reddish-brown   precipitate  of  uropittine- 
calcium  falls  down. 


Xanthine,  05H4N403. — 1.  From  Calculi.  Dissolve  a 
small  portion  of  a  xanthine  calculus  in  caustic  potash, 
pass  carbonic  acid  through  the  solution,  and  wash  the 
precipitate  with  water. 


XANTHINE.  191 

2.  From    Urine. — Precipitate    with   baryta    water, 
filter,  evaporate  to  a  syrup,  and  set  aside  to  crystallise. 
Eemove  the  crystals,  dilute  the  mother  liquid,  and  boil 
with  cupric  acetate.      Wash  the   precipitate  thereby 
produced,  dissolve  in  warm  nitric  acid,  reprecipitate 
with  silver  nitrate,  wash  the  precipitate,  and  crystallise 
it  from  dilute  nitric  acid.      Wash   the   crystals   with 
ammoniacal  silver  solution,  decompose  by  sulphuretted 
hydrogen,  filter,  evaporate  to  a  low  bulk,  and  wash 
with  a  little  water  the  deposit  of  xanthwe. 

3.  From  Flesh,  fyc. — Extract  the  pounded  substance 
successively  with  warm  alcohol  and  water,  evaporate 
the  mixed  extracts  and  filter,  precipitate  the  filtrate 
with  neutral  and  basic  lead  and  with  mercuric  acetate. 
Treat  the  precipitates  by  the  two  latter  with  hydro- 
thion  in  water,  filter,  and    evaporate.      Sarkine  and 
xanthine  will  be  deposited;  separate  by  crystallising 
from    hydrochloric    acid;    the   first   crystals   will   be 
xanthine   hydrochlorate,    while  the  mother  liquid  will 
contain  sarltine  (q.v.).     Dissolve  the  former  in  caustic 
potash,  pass  carbonic  acid  in  excess  through  the  solu- 
tion, and  wash  the  precipitate  of  xanthine. 

4.  Xanthine    is    almost    insoluble    in    water,    in- 
soluble   in    alcohol    and   ether.     From   hot  water    it 
separates  in  white  flocks.     An  aqueous  solution  rapidly 
decomposes.     It   is   nearly  insoluble  in   hydrochloric 
acid. 

5.  Heat   a  little    dry  xanthine  in  a  tube ;    it  will 
evolve  ammonium  carbonate  and  cyanide,  and  a  fetid 
oil. 

6.  Dissolve  xanthine  in  hot  ammonia;  on  cooling 


192  XANTHINE. 

crystals  of  a  compound  of  xanthine  and  ammonia  will 
be  formed. 

7.  Dissolve    xanthine   in    hot    hydrochloric    acid. 
When  cool  add  platinic  chloride;  a  yellow  crystalline 
precipitate  of  a  double  salt  will  ensue. 

8.  To  a  dilute  solution  of  xanthine  in  nitric  acid, 
add  silver  nitrate  ;  no  precipitate  will  be  produced  (see 
hypoxanthine). 

9.  Xanthine  is    soluble   in  concentrated   sulphuric 
acid,  and  the  solution  is  not  precipitated  by  water. 

10.  To  a  solution  of  xanthine  in  water  add  mercuric 
chloride  or  cupric  acetate ;  a  precipitate,  white  in  the 
first  case,  green  in  the  second,  will  be  formed. 

11.  Dissolve  a  very  little  sodium  in  mercury,  and 
place  in  an  aqueous  solution  of  xanthine ;  the  latter 
will  be  gradually  reduced  to  hypoxanthine. 


ALPHABETICAL   INDEX. 


Acetic  acid,  61 
Albumen  of  eggs,  63 

serum,  33,  83 
Alcohol,  65 
Allantoine,  56,  67 
Alloxan,  59,  67 
Amyloid  substance,  5,  69 
Animal  quinoidine,  69 

Beef  tea,  37 

Benzoic  acid,  70 

Biliary  function,  14 

Bile,  16,  19,  21,  71 

Bilifuscine,  18,  75 

Bilirubine,  18,  76 

Biliverdine,  18,  77 

Blood,  system.     Analysis,  79 

„      corpuscles,  26,  30,  35 
Bones,  46 
Brain,  40,  85 
Breath,  57 
Butyric  acid,  90 
Butyro-luteine,  149 

Calculi,  biliary,  91 

„     intestinal,  94 

„     prostatic,  94 

„     urinary,  94 
Cartilage,  45 
Caseine,  97 
Cerebric  acid,  28,  41,  98 


Cerebrine,  41,  99,  100 
Cholera,  blood  in,  31 
Cholesterine,  18,  42,  102 
Cholic  acid,  17, 102 
Choline,  18,  41,  141 
Cholocyanine,  78 
Cholothalline,  78 
Chondrine,  103 
Chyle,  26,  105 
Chyme,  11,  106 
Connective  tissue,  43,  108 
Cornea,  45 
Corpora  lutea,  144 
Cruentine,  108 
Cystine,  111 
Cysto-luteine,  149 

Dentine  and  enamel,  47 

Dextrine,  5,  112 

Diabetes,  9 

Diabetic  sugar  or  Glykose,  125 

Diastase,  4 

Digestion,  1, 10 

Elastic  tissue,  113 
Emulsine  or  synaptase,  4 
Excretine,  113 
Excretolic  acid,  114 


Fseces,  58, 114 
Fats,  22, 115 


13 


194 


ALPHABETICAL    INDEX. 


Fatty  degeneration,  25 
Fibrine,  32,  117 

Fluopittine  and  fluorescentine,  118 
Formic  acid,  61,  118 

Gases  in  intestines,  59 
Gastric  juice,  10,  119 
Gelatine,  43,  120 
Globuline,  121 

Glycerophosphoric  acid,  41,  90 
Glykocholie  acid,  17,  121 
Glykogen,  7,  122 
Glykogeny,  3.  . 
Glykokoll,  18 
Glykose  or  glucose,  125 
Guanine,  127 

Hair,  128 
Hematic  acid,  30 
Hematine,  28,  128 
Hemato-crystalline,  27,  80 
Hippuric  acid,  55,  130 
Hyaline,  45 
Hypoxanthine,  131 

Inosic  acid,  132 
Inosite,  133 
Intestino-luteine,  150 

Kidneys,  54 
Kreatine,  55,  134 
Kreatinine,  55,  134 
Kreatylic  acid,  156 
Kryptophanic  acid,  55,  136 

Lactic  acid,  47,  138 

Lecithine,  41,  139 

Leucine  and  leucic  acid,  142,  144 

Liver,  52 

Luteine,  144 

Lymph,  151 

Margaric  aoid,  41 
Melanine,  152 


Milk,  152 
Mucine,  154 
Muscles,  36,  39,  155 
Myeline,  43, 156 
Myockrome,  37 
Myosine,  36,  157 

Nerves,  40, 157 
Neurine,  19,  41 

Oleic  acid,  41 
Oleopnosplioric  acid,  158 
Omicholic  acid,  55,  159 
Omicholine,  55,  160 
Osseine,  46,  120 
Osteomalacia,  47 
Ovaries,  52 

Pancreas,  52 

Pancreatic  juice,  13,  21,  161 

Paraglobuline,  29,  33,  84 

Paraphanic  acid,  56 

Peptones,  11,  20 

Pigment,  44 

Protagon,  41,  162 

Ptyaline,  3,  163 

Pus  and  Pyine,  48,  164, 165 

Pyaemia,  49 

Pyocyanine,  49,  165 

Rencnli,  51 

Rhachitis,  47 

Saliva,  1,  166 

Sarkosine,  55,  166 

Sero-leutine,  150 

Serum,  33 

Starch,  4 

Spleen,  49 

Stomach  digestion,  14 

Succinic  acid,  167 

Sulphocyanic  acid,  168 

Sulphocyanides  (rhodanates),  3 


ALPHABETICAL   INDEX. 


195 


Sweat,  56, 169 
Synovia,  45, 170 
Syntonine,  36,  170 

Taurine,  17,  171 
Taurocholic  acid,  17,  171 
Teeth,  47 
Thymus,  50 
Thyroid,  51 
Trimetliylamine,  172 
Tyrosine,  172 


Urea,  55,  173 

„   estimation  of,  175 
Urine,  systematic  analysis  of,  178 

„       sediments  in,  183 

„       oil,  186 
Urochrome,  186 
Urocyanine,  188 
Uromelanine,  54,  188 
Uropittine,  54,  190 

Xanthine,  190 


PRINTED    EY   J.    E.    ADLAED,    BARTHOLOMEW   CLOSE. 


DATE   DUE  SLIP 

UNIVERSITY  OF  CALIFORNIA  MEDICAL  SCHOOL  LIBRARY 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


.JAY 


14  DAY 

JftN  23  1970 

RETURNED 

JAN  12  1970 


lHi-4,'20 


